I'm biased, but I could see Lightwhale play a key role in this setup. You could start small, two nodes with Lightwhale in a Docker Swarm cluster. Run your server in a container. Leverage Swarm's load balancing to distribute connections to the nodes. You go l can even experiment with this in Proxmox and run the Lightwhale nodes as VMs if you like.
You get a minimum effort OS to host your game on, and the option to distribute it.
You get a minimum effort OS to host your game on, and the option to distribute it.