given that you’re looking at vpns I’m assuming you can’t do port forwarding on your network. Am I right?

Have you seen zerotier? it lets you create a virtual network. super easy to setup but in the default configuration you’re relying on a third party service. not sure if that’s ok with you.

The most user-friendly way to do it is hosting it on a https server. for this you need a reverse proxy. checkout caddy. or if you’re on docker try traefik.

Most home isps don’t let you open port 80 and 443 so you have to use alternative ports which is ok for https but it will make renewing certificates really hard. you have to do it with dns. if it works great. but in my experience it was usually finicky.

A cheap android box + armbianOs is also an option if you’re looking for low power. I have a 7watt one that’s running 24/7 for the last few years.

not exactly what you want. but check out gaming on whales Wolf docs. it’s configured for gpu accelerated X11 apps on docker. if I recall correctly one of the documents explained settings up nvidia drivers on docker completely.