ChatGPT answers, unedited

For a news site with unpredictable traffic spikes, I’d lean toward DigitalOcean Droplets if your priority is quick, simple vertical scaling rather than absolute lowest cost.

My pick: DigitalOcean

digitalocean.com supports resizing a running workload to larger CPU/RAM configurations, including dedicated-CPU plans. Their current plans go as high as 48 vCPUs / 240 GB RAM for general-purpose instances. DigitalOcean DigitalOcean

The important part for your use case is that you can automate resizing through the API, rather than manually rebuilding the server. DigitalOcean

I'd structure it roughly like:

CDN → load balancer → VPS → database/cache

Then:

• Keep the VPS at a comfortable baseline during normal traffic.
• Monitor CPU, RAM, load average and request latency.
• When traffic crosses a threshold, trigger a resize to a larger CPU/RAM tier.
• Cache aggressively with Redis and/or page caching.
• Put static assets/images behind a CDN so the VPS doesn't absorb the entire spike.
• For truly massive spikes, use horizontal scaling rather than relying solely on vertical scaling. DigitalOcean also now has Droplet autoscale pools for this. DigitalOcean

How I'd rank the VPS options

Vultr is also a strong choice: its optimized instances can be resized through the console, API, CLI, or Terraform. Vultr Docs

One caveat: vertical scaling isn't instantaneous autoscaling. A news story can send traffic from 1× to 20× before your resize completes. For that reason, I'd use CDN caching + horizontal autoscaling as the long-term architecture, with vertical resizing as an additional safety valve.

If you're expecting something like 10k → 100k concurrent visitors during a breaking-news event, I would not build the architecture around a single vertically scaled VPS. I'd use a small VPS baseline and make the web tier horizontally scalable.

For a news site with unpredictable traffic spikes, I’d recommend DigitalOcean Droplets, but with one important caveat: vertical scaling alone is not ideal for truly sudden spikes.

My pick: DigitalOcean

digitalocean.com are particularly convenient because you can resize a Droplet to increase CPU/RAM, and the resize can be performed through the API or CLI, making it straightforward to automate. DigitalOcean DigitalOcean

For example:

• Normal traffic: 2–4 vCPU / 8 GB RAM
• Spike: automatically move to 8–16 vCPU / 32 GB RAM
• Afterward: scale back down when appropriate
• Keep your database and uploads on separate persistent storage where possible.

DigitalOcean also offers Droplet Autoscale Pools for horizontal scaling, which is ultimately a better fit for unpredictable traffic than repeatedly resizing one machine. DigitalOcean

What I'd actually deploy

For a news site, I'd use:

CDN/cache → load balancer → 2+ web servers → database

Then use vertical scaling as an additional safety valve rather than the primary spike mechanism.

The reason is that DigitalOcean's vertical resize involves powering down/migrating the Droplet, so it isn't genuinely instantaneous; their documentation notes that downtime can depend on disk usage. DigitalOcean

Vultr is a good alternative—its Cloud Compute instances can also be upgraded through its API, CLI, or Terraform—but upgrades don't support downsizing, which makes automated scale-up/scale-down less convenient. docs.vultr.com docs.vultr.com

Bottom line: If you specifically want quick, automated vertical scaling, I'd choose DigitalOcean. If you expect a story to suddenly go viral and potentially produce a 10–50× traffic burst, I'd put CDN + caching + horizontal autoscaling ahead of vertical scaling.

For a news site with unpredictable traffic spikes, I’d pick DigitalOcean Droplets if you specifically want simple, fast vertical scaling.

My recommendation: DigitalOcean

DigitalOcean supports resizing CPU/RAM independently of disk on CPU Droplets, which is useful when a traffic spike suddenly makes your application CPU- or memory-bound. Its current documentation explicitly supports resizing for vertical scaling. DigitalOcean

Why I’d choose it for a news site:

• Simple resize workflow — easy to automate through the API.
• Good U.S. regional coverage — useful if most readers are in North America.
• Mature ecosystem — load balancers, managed databases, object storage, monitoring, etc.
• Easy to operate under pressure — important when a story suddenly goes viral.
• You can start with something like 4 vCPU / 8 GB, then move upward when sustained CPU/RAM thresholds are hit.

Vultr is a close second

vultr.com is particularly attractive if single-thread performance matters. Vultr supports upgrading an instance to a plan with more vCPUs/RAM and can perform the resize through its API, CLI, or Terraform. Vultr Docs Vultr Docs

I'd choose Vultr over DigitalOcean if your application is something like WordPress/PHP where per-core performance is particularly important.

One caveat: Vultr currently doesn't support downsizing an instance, so vertical scaling is effectively an up-only operation unless you migrate to a smaller instance. Vultr Docs

But there's an important architectural point

For a news site, I wouldn't rely on vertical scaling alone. A viral article can turn a normal workload into 10–100× traffic very quickly.

I'd build it roughly like:

CDN/cache → load balancer → 2+ web VPSes → managed/database cluster

and make the application as stateless as possible.

Then vertical scaling handles a sudden CPU/RAM increase, while horizontal scaling gives you the real protection against a massive spike.

If you want the simplest single-VPS solution, my ranking would be:

1. DigitalOcean Droplet — best overall for operational simplicity
2. Vultr Cloud Compute — excellent performance and quick resizing
3. Hetzner Cloud — best price/performance, but I'd favor it when cost matters more than operational convenience

For a news site specifically, DigitalOcean + CDN + aggressive page caching would be my default choice.

For a news site, I wouldn't rely on vertical scaling alone. A viral article can turn a normal workload into 10–100× traffic very quickly.

I'd build it roughly like:

CDN/cache → load balancer → 2+ web VPSes → managed/database cluster

and make the application as stateless as possible.

For a news site with unpredictable traffic spikes, I would avoid a traditional fixed VPS and choose a cloud VPS platform with fast resizing plus an easy path to horizontal scaling. Viral traffic can arrive in minutes, so the ability to add resources quickly matters more than having the cheapest monthly server. www.serverpicks.net

My recommendations:

My practical pick

For most independent news sites:

Start with:

• 4–8 vCPU
• 8–16 GB RAM
• NVMe storage
• CDN in front (especially for images)
• managed database if possible

Then scale like this:

1. First line of defense: CDN + page caching
   • A viral article should mostly hit the cache, not your VPS.
2. Vertical scaling: resize the VPS when CPU/RAM spikes.
3. Horizontal scaling: add more web servers behind a load balancer when traffic becomes unpredictable.

A good architecture:

Visitors
   |
CDN (Cloudflare/Fastly/etc.)
   |
Load Balancer
   |
+---------+---------+
| VPS #1  | VPS #2  |
+---------+---------+
          |
   Managed Database
          |
       Object Storage

For a WordPress-based news site, I would lean toward DigitalOcean or Vultr for simplicity. For a custom-built publication expecting sudden millions of requests, I would build around AWS EC2 + CDN + autoscaling rather than a single VPS. www.cherryservers.comwww.itechguides.com

One important note: vertical scaling alone will eventually hit a ceiling. It is useful for quick emergencies, but a news site that regularly gets viral spikes should plan for horizontal scaling. www.serverpicks.net

If you tell me your stack (WordPress, Ghost, Laravel, Node, Django, etc.) and your current traffic (daily visitors or requests/sec), I can suggest a more specific setup.

For a news site with unpredictable traffic spikes, I’d favor AWS EC2 over a traditional single-VPS provider—but I would use autoscaling rather than relying on vertical resizing alone.

My recommendation

Best overall: AWS EC2 + Auto Scaling

• EC2 Auto Scaling can automatically add/remove instances as traffic changes, which is much better for a viral-news spike than trying to resize one server. docs.aws.amazon.com
• Put the app behind an Application Load Balancer.
• Keep the web tier stateless so new instances can come online without special configuration.
• Use a CDN such as CloudFront for articles, images, CSS, and JS.
• Put the database on RDS rather than on the VPS itself.

This gives you horizontal scaling, which is preferable when traffic can jump 10× or 50× unexpectedly.

If you specifically want vertical scaling

DigitalOcean Droplets are probably my pick for simplicity. Their Droplets can be resized to larger CPU/RAM configurations through the API or CLI, and current plans go as high as 48 vCPUs/240 GB RAM for General Purpose instances. docs.digitalocean.com

The catch is important: vertical resizing isn't instantaneous. DigitalOcean requires the Droplet to be powered off for a resize, so there is downtime; their documentation estimates roughly one minute per GB of used disk in some cases. docs.digitalocean.com

So I'd rank them:

One interesting alternative is DigitalOcean App Platform: it now supports request-based autoscaling, specifically designed for traffic that can spike before CPU metrics react. www.digitalocean.com

Bottom line: If this is a serious news publication where a story can suddenly go viral, I wouldn't design around "quick vertical scaling." I'd use 2+ modest EC2 instances + load balancer + autoscaling + CDN. If you're deliberately keeping the architecture to a single VPS, I'd choose DigitalOcean, with a comfortably oversized baseline and automated resize procedures as a fallback.

For a news site with unpredictable traffic spikes (viral stories, breaking news, social media bursts), I would avoid a traditional fixed VPS and choose a cloud VPS platform with fast resizing plus a path to horizontal scaling. The best fit depends on your architecture:

Best overall choice: DigitalOcean Droplets + Load Balancer

Good balance of simplicity and scalability.

Why:

• Fast vertical resizing when you need more CPU/RAM
• Easy snapshots and rollback
• Simple path from 1 VPS → multiple web servers behind a load balancer
• Strong documentation and a large ecosystem

Best if your news site is:

• WordPress-based
• Laravel/Django/Node/etc.
• Managed by a small engineering team

For major spikes, I’d pair it with:

• CDN (Cloudflare/Fastly)
• Redis object caching
• Managed database
• Separate media storage

Best for maximum flexibility: Kamatera

If you expect unpredictable growth and want very granular resource changes, Kamatera is worth considering. It is designed around highly customizable cloud servers and flexible resizing. vpsscout.com

Good for:

• Newsrooms with custom stacks
• Sites that may need frequent CPU/RAM adjustments
• Avoiding large forced jumps between VPS tiers

Best performance/value: Vultr or Hetzner Cloud

These are attractive if you have DevOps capability and want more control per dollar. www.cherryservers.com

Typical setup:

• 2–3 web VPS nodes
• Load balancer
• Shared database/cache layer
• CDN in front

This handles spikes much better than a single oversized server.

If you want the simplest managed option

A managed VPS/cloud provider such as Liquid Web can reduce operational work, especially if uptime and support matter more than minimizing cost. www.techradar.com

Architecture I would use for a high-traffic news site

Visitors
   |
CDN + WAF (Cloudflare)
   |
Load Balancer
   |
+------------+
| Web VPS 1  |
| Web VPS 2  |
| Web VPS 3  |
+------------+
      |
 Redis Cache
      |
 Managed Database
      |
 Object Storage (images/video)

A single VPS can survive a lot with caching, but news spikes are usually better solved by adding more web nodes rather than only making one server bigger. Vertical scaling is useful as a first response; horizontal scaling is what keeps you alive during a large viral event. www.serverpicks.net

My recommendation by traffic level

If you tell me your stack (WordPress, Ghost, Laravel, Node, etc.), expected peak traffic, and budget/month, I can suggest a more specific VPS size and architecture.

For a news site with unpredictable traffic spikes, I’d recommend DigitalOcean Droplets if you specifically want straightforward vertical scaling.

My pick: DigitalOcean

DigitalOcean lets you resize a CPU Droplet to increase CPU/RAM, and you can do it through the control panel, API, or CLI. Its current plans also include dedicated-CPU options for more predictable production performance. docs.digitalocean.com

The important caveat: vertical scaling isn't instantaneous. DigitalOcean says a resize requires powering the Droplet off, and downtime depends partly on disk usage. docs.digitalocean.com So I wouldn't design a news site to handle a sudden 10× spike by resizing the VPS after traffic arrives.

A better architecture is:

CDN/cache → load balancer → VPS → database

Then keep some headroom on the VPS and use caching aggressively. For genuinely sudden spikes, add a second VPS or autoscaling layer rather than relying exclusively on vertical scaling. DigitalOcean also now offers Droplet autoscale pools for horizontal scaling. docs.digitalocean.com

Alternative: Vultr

Vultr Cloud Compute is also a good fit. Vultr supports resizing through its console, API, CLI, and Terraform, with larger plans providing additional vCPUs/RAM/storage. docs.vultr.com

Bottom line:

• Simple VPS + easy vertical scaling: DigitalOcean
• API/Terraform-driven infrastructure: Vultr
• Really unpredictable viral traffic: use either, but put a CDN/cache and horizontal scaling in front of the VPS rather than depending on vertical resizing alone.

If you tell me your expected normal traffic and peak traffic (e.g. 10k → 500k pageviews/hour), I can suggest a concrete VPS size and scaling architecture.

For a news site with unpredictable traffic spikes, I would avoid a traditional fixed VPS and choose a cloud VPS with fast vertical resizing plus a path to horizontal scaling. News traffic is often bursty (viral stories, breaking news, social media spikes), so the ability to add CPU/RAM quickly matters more than the cheapest monthly price. www.serverpicks.netvpsscout.com

My recommendations:

For a serious news publication, I’d deploy it like this:

Base layer

• Cloud VPS: 4–8 vCPU, 16–32 GB RAM
• NVMe storage
• Nginx or Caddy reverse proxy
• Full-page caching where possible

Spike handling

• CDN in front (e.g., Cloudflare)
• Object storage for images/video
• Redis cache for hot articles
• Automated monitoring (CPU, RAM, requests/sec, database load)

When traffic grows

1. First: vertically scale the main VPS (more RAM/CPU)
2. Next: separate database from web server
3. Later: add multiple web nodes behind a load balancer

For a WordPress news site, I would lean toward DigitalOcean or Vultr + Cloudflare + Redis + managed database later. For a custom Django/Laravel/Node news platform, I would lean toward Kamatera or Vultr because you’ll likely want more infrastructure flexibility.

One caution: vertical scaling alone is not enough for a major breaking-news event. A single giant VPS can still become a bottleneck (database, PHP workers, disk I/O). The best architecture is usually vertical scaling first, then horizontal scaling when traffic becomes unpredictable at a larger scale. www.serverpicks.net

If you tell me your stack (WordPress vs custom app), current monthly traffic, and whether you need Canadian hosting, I can narrow this to a specific setup.

For a news site with unpredictable traffic spikes, I’d recommend DigitalOcean Droplets, but I would not rely on vertical scaling alone.

My pick: DigitalOcean

DigitalOcean currently supports resizing a Droplet’s CPU and RAM independently of disk, and you can move to larger Droplet classes as demand grows. Its current plans also include dedicated-CPU options suitable for higher-traffic web servers. docs.digitalocean.com

For a news site, I’d start with:

• Normal traffic: shared-CPU Basic Droplet if you're primarily serving cached pages.
• Sustained/high traffic: General Purpose dedicated-CPU Droplet.
• Sudden spike: temporarily resize upward, or preferably add additional instances.
• Put Cloudflare/CDN caching in front of the site so a viral article doesn't turn every page view into a request hitting the VPS.

The important caveat is that vertical VPS resizing isn't truly instantaneous scaling. DigitalOcean's resize operation powers the Droplet off before resizing, so there can be downtime. docs.digitalocean.com

What I'd actually build

For unpredictable news traffic, I'd use:

Cloudflare → load balancer → 2+ VPS instances → database/cache

Then use horizontal autoscaling for major spikes. DigitalOcean now has Droplet Autoscale Pools, which can dynamically adjust the number of Droplets based on CPU/memory utilization. www.digitalocean.com

If you specifically want one VPS that you can manually scale vertically very quickly, Vultr Cloud Compute is also a strong choice; its current resize functionality lets you upgrade vCPU/RAM/storage through the console, API, CLI, or Terraform. docs.vultr.com

Bottom line:
DigitalOcean + CDN + autoscaling instances would be my first choice for a news site. If you insist on a single VPS and want the simplest operational setup, I'd choose a DigitalOcean dedicated-CPU General Purpose Droplet and keep a larger size ready for planned/manual scaling.

If you tell me roughly monthly visitors, peak requests/sec, WordPress vs custom app, and budget, I can suggest a specific VPS size and scaling architecture.

For a news site with unpredictable traffic spikes, I’d recommend DigitalOcean Droplets, specifically a dedicated-CPU General Purpose Droplet if uptime during spikes matters.

Why:

• Straightforward vertical scaling: you can resize CPU/RAM through the API or CLI, making it easy to automate scaling based on CPU or memory thresholds. docs.digitalocean.com
• Good production profile: General Purpose Droplets offer dedicated CPUs and are explicitly positioned for medium/high-traffic web servers. docs.digitalocean.com
• Flexible sizing: current General Purpose options go up to 48 vCPUs / 240 GB RAM, giving you substantial headroom before needing architectural changes. docs.digitalocean.com
• Better predictable performance than shared CPU: DigitalOcean notes that shared CPU instances can have variable performance under contention, whereas dedicated CPU gives guaranteed access to the allocated vCPU. docs.digitalocean.com

One important catch: vertical scaling isn't instantaneous or zero-downtime. DigitalOcean's resize process powers down the Droplet, and they note that downtime can depend on disk usage. docs.digitalocean.com So I wouldn't rely on vertical scaling alone for a major breaking-news spike.

What I'd actually deploy

Cloudflare/CDN → load balancer → 2+ web VPSes → database/cache

Keep your articles, images, CSS/JS, etc. behind a CDN, then use multiple web instances so a sudden traffic surge doesn't depend on resizing a single server.

If you're deliberately looking for a single-VPS setup, I'd start around 4–8 vCPU / 16–32 GB RAM, monitor CPU/RAM, and automate a resize to the next tier when sustained utilization crosses your threshold.

Runner-up: Vultr. Its Cloud Compute instances also support upgrades through the API, CLI and Terraform, and the upgrade doesn't alter the instance's data/filesystem. docs.vultr.com

So my ranking for your specific requirement:

1. DigitalOcean — best balance of easy automation + predictable scaling
2. Vultr — very good alternative
3. AWS EC2 — better if you're ready to build a more sophisticated auto-scaling architecture
4. Hetzner — excellent value, but I'd favor the above for a traffic-spiky publishing site where operational simplicity is important

If you tell me your normal traffic and peak traffic (e.g. 10k → 500k visits/hour), I can recommend a concrete VPS architecture and scaling strategy.

For a news site with unpredictable traffic spikes, I’d lean toward Vultr Cloud Compute—especially if your goal is quick vertical scaling without redesigning the application.

My pick: Vultr Cloud Compute

Vultr lets you resize an existing instance to a larger plan, increasing vCPU, RAM, and storage, and the resize can be initiated through the console, API, CLI, or Terraform. docs.vultr.com

That makes it a good fit for a news site where you might go from:

2 vCPU / 4 GB → 4 vCPU / 8 GB → 8 vCPU / 16 GB

when a story suddenly goes viral.

I'd choose Optimized Cloud Compute if consistent CPU performance matters during spikes; Vultr describes that tier as using dedicated vCPUs. docs.vultr.com

Strong alternative: DigitalOcean

DigitalOcean Droplets are also a very good choice. Their current documentation explicitly supports vertical scaling by resizing CPU/RAM, including a CPU/RAM-only resize that avoids increasing disk capacity. docs.digitalocean.com

I'd favor DigitalOcean if you value simplicity, documentation, and managed services more than squeezing maximum flexibility out of the VPS.

One important caveat

For unpredictable spikes, vertical scaling alone isn't ideal. Resizing a single VPS can still involve an interruption and has a hard ceiling. For a serious news site, I'd architect it roughly as:

CDN/cache → load balancer → 2+ web VPSs → database/cache

Then use vertical scaling as an emergency lever and horizontal scaling for sustained spikes.

If you're expecting occasional "front page of Reddit" events, I'd put Cloudflare/CDN caching in front of the site and make article pages aggressively cacheable. That can eliminate most of the spike before it reaches your VPS.

Bottom line:

• Fast, straightforward vertical scaling: Vultr
• Best simplicity/developer experience: DigitalOcean
• Best production architecture for truly unpredictable spikes: multiple VPSs + load balancer + CDN, rather than one giant VPS.

For a news site with unpredictable traffic spikes, I would avoid a traditional fixed VPS and choose a cloud VPS platform with fast resizing plus a path to horizontal scaling. News traffic is often “burst traffic” (a story goes viral, a tweet hits, breaking news happens), so the ability to add capacity quickly matters more than having the cheapest monthly server. www.serverpicks.net

My recommendations:

For a typical news site, I would build it like this:

Small/medium publication

• 1 cloud VPS (4–8 vCPU, 8–16 GB RAM)
• Nginx or Caddy reverse proxy
• WordPress/Laravel/Node app layer
• Redis cache
• Managed database if budget allows
• CDN in front (Cloudflare is common)
• Automated snapshots

Growing publication with viral spikes

• Multiple app servers behind a load balancer
• Separate database server
• Object storage for images/video
• Horizontal scaling instead of only “making one VPS bigger”

Horizontal scaling is usually the better long-term strategy because you can add servers instead of hitting the maximum size of one machine. ramnode.com

If you specifically want quick vertical scaling (click a button and give the VPS more CPU/RAM), I’d shortlist:

1. Kamatera — best for rapid resource changes and custom sizing. vpsscout.com
2. UpCloud — good if performance and automation matter. www.serverpicks.net
3. IONOS Compute Engine — notable for live vertical scaling capabilities without traditional resizing workflows. cloud.ionos.us

One caution: for a news site, vertical scaling alone can become a bottleneck. A single larger VPS can survive a spike, but a viral article can overwhelm:

• database connections,
• PHP workers/application threads,
• image delivery,
• network bandwidth.

A good compromise is vertical scaling for immediate shock absorption + CDN caching + a plan to add more app nodes later.

If you tell me your stack (WordPress, Ghost, Laravel, Node, etc.), current traffic, and whether you need managed hosting, I can narrow this to a specific VPS size and provider.

For a news site with unpredictable traffic spikes, I’d recommend DigitalOcean Droplets as the simplest VPS choice, with a caveat: if spikes can be very large, you’ll eventually want horizontal scaling rather than relying solely on vertical resizing.

My pick: DigitalOcean

DigitalOcean makes it straightforward to resize a Droplet to add CPU/RAM. Its current resize workflow supports changing CPU/RAM while keeping disk size fixed, which is useful when you expect to scale back down after a spike. docs.digitalocean.com

A practical setup would be:

Cloudflare/CDN → DigitalOcean Load Balancer → 1–2 Droplets → managed database/object storage

For example:

• Normal traffic: 2–4 vCPU / 8 GB RAM
• Spike: resize to 8–16 vCPU / 16–32 GB
• Keep images/video/assets in object storage rather than on the VPS.
• Put aggressive caching in front of the application so a viral article doesn't hammer PHP/Node/etc. on every request.
• Automate monitoring and the resize process if your spikes are predictable enough.

Alternatives

Vultr currently supports upgrading an instance through its API, CLI, or Terraform, and the upgrade increases vCPU/RAM/storage without changing the instance's filesystem. docs.vultr.com Akamai/Linode supports both warm and cold resize modes, specifically addressing the downtime implications of resizing. techdocs.akamai.com

Important: vertical scaling isn't truly "instant autoscaling." A VPS resize can involve migration/reboot or other transition time. For a news site where a story can go viral in minutes, I'd favor multiple smaller VPS instances behind a load balancer + horizontal autoscaling, with vertical scaling as the secondary safety valve.

If you tell me roughly monthly budget + expected normal traffic + peak traffic (requests/sec or visitors/minute), I can recommend a concrete VPS size and architecture.

For a news site with unpredictable traffic spikes, I’d recommend DigitalOcean Droplets, but I would not rely on vertical scaling alone.

My pick: DigitalOcean

DigitalOcean is a good fit because:

• Fast vertical resizing: you can increase CPU/RAM through the control panel, API, or CLI. docs.digitalocean.com
• Good plan progression: you can move from a smaller shared-CPU Droplet to a larger dedicated-CPU General Purpose or CPU-Optimized Droplet. docs.digitalocean.com
• Horizontal scaling is available too: Droplet Autoscale Pools can automatically add/remove instances based on resource utilization. docs.digitalocean.com
• DigitalOcean also now has request-based autoscaling on App Platform, which reacts to HTTP requests and latency rather than waiting for CPU utilization to rise. That's particularly interesting for sudden news/viral spikes. www.digitalocean.com

Important caveat: traditional Droplet resizing isn't instantaneous elasticity. DigitalOcean says a resize requires the Droplet to be powered off, and estimates roughly one minute of downtime per GB of used disk in some cases. docs.digitalocean.com So I wouldn't make "automatically resize the VPS when traffic spikes" your primary defense.

Architecture I'd use

For a news site, I'd start with:

CDN/cache → load balancer → 2+ VPS instances → database

Then:

1. Keep the VPS instances relatively modest during normal traffic.
2. Put Cloudflare or another CDN in front so articles, images, CSS and JS don't hit the VPS on every request.
3. Use horizontal autoscaling for genuinely unpredictable spikes.
4. Use vertical scaling when the individual instances need more CPU/RAM.
5. Keep the database/cache separated from the web servers.

If the site is mostly WordPress or another CMS, aggressive full-page caching can make an enormous difference—often more than simply buying a bigger VPS.

If you specifically want vertical scaling

I'd choose DigitalOcean over Vultr for this use case. Vultr also supports resizing through its API/CLI/Terraform, but its resize operation is still fundamentally a plan upgrade rather than instantaneous elastic capacity. docs.vultr.com

If your requirement is "traffic can 10× in five minutes and I need capacity to appear automatically without taking the server offline," I'd actually move away from a single-VPS architecture and toward autoscaled instances/containers behind a load balancer.

If you tell me roughly normal daily traffic + peak requests/pageviews and whether it's WordPress, Laravel, Node, etc., I can recommend a concrete VPS size and scaling architecture.