I use something called What’s Up Docker to check for docker updates. It integrates nicely with Home Assistant, so I made a card on my server state dashboard that shows which containers have updates available. I’ll check every so often and update my docker-compose files.
Agreed with this, they may want the setup but have no interest in managing it, no matter how simple you get it. If you do it for them you might be setting yourself up as their permanent support.
I’d gauge how interested they actually are, and make sure they’re willing to learn enough to follow basic maintenance routines.
Win 7 64-bit handily beats any distro of Linux at .69% (nice). Comparing only to 32-bit isn’t a fair comparison. Not that I’m against using Linux, I use Pop_os on a spare computer as a Linux test bed for gaming.