Yeah DMZ game servers are a good idea. I’d image one with something immutable, get it all set up and then “have at ye!”. If someone pwns it you just yank the cord. Since they are identical you can have them both set up, someone owns it, you yank/replace and your friends just go right back to it.

If I did something like this I wouldn’t even ssh into them, just have them in some dark corner with a small kb/m/monitor. Totally different subnet.