If you could guarantee that you could keep your server running (or at least save the game before you crash/reboot/…) that would probably work. But running your own server requires some coding to change the URL clients connect to, see:
https://forum.vassalengine.org/t/setup-own-server/3659/1
I tried now to see if switching to Peer-to-Peer mode (under Preferences > Server) would help, you could keep your VASSAL running like that, but you need to Invite people to join, rather than having them connect. So that wouldn’t be practical.