From time to time I do need to reboot the server to apply OS updates, but that usually only takes a few minutes. If the game is down, but the website is up, then we know NWN crashed (it's on the same machine). It's configured to restart the game if it crashes.
When running natively, there's a way to regularly save the instance and reload the state on startup, but this one is running in a docker container. I've not been able to get the reload part working in docker, hence things get reset any time the game crashes or we reboot.