It looks it could be served pretty easily as a static site for very little cost. I try to use WP2Static whenever possible. It's a plugin that crawls the WordPress site and deploys a static version to a server of your choice, like S3/CloudFront or Netlify.
If you're the only person who accesses it, you can run the WordPress instance locally in Docker via https://lokl.dev/ and pay only for the static site costs, which are usually laughably small. If you want managed hosting, there are proprietary options like HardyPess and Strattic. Or you can use any commodity host and install WP2Static. I'm developing a low-cost ($10-15/mo) WP2Static-based hosting service at https://app.staticweb.io that should be very easy to get started with, but we haven't quite gotten ready to launch yet. The servers work great, but we don't yet have a support ticket system set up. If you want to try it and need support, you can just email me at john@app.staticweb.io without the "app.". Even if you don't try it, feel free to email with any questions about WP2Static.
The only hitch is that the site seems very large. Some people report slowness with WP2Static crawls, but all the sites I've tried have been fine, so YMMV. I've done some work in an addon[0] to support incremental crawling, but it needs a bit more love to make sure it's reliable. I lack a slow site to test it on and fine-tune it.
[0] https://github.com/leonstafford/wp2static-addon-advanced-cra...