I definitely recommend nix. In fact, I prototyped my NixOS server in a VM and then committed my config to a git repository to clone on the real server later

If you copy the contents of the virtual hard disk used by to VM to a real disk, then you can just boot your server from that real disk. You'll probably have to reconfigure some hardware and network stuff but it should be super simple.

Nix might be the answer for that, or ansible. You'll still have to reinstall, but the second time will be super easy.