I have a possible thing I discovered recently that you might like (especially if the machine you leave screened is on your home LAN): https://tailscale.com/ has a free tier that lets you pretty trivially set up a VPN (with separate DNS and everything) from anywhere, to anywhere (and the name resolves correctly from anywhere as well). Avoids having to map ports etc. Anyway I've been playing with it and it's a neat toy at least, for sure, being able to access anything in my network from anywhere without having to manage port-mapping at my router, etc.

I'm actually going to use it to set up my own cloud dev I can access from anywhere, but it has tremendous utility beyond that