Or use Fedora with kickstart/modified atomic base image/bootable containers.

Yea I need to think of a good way to automate updates..

`unattended-upgrades` package on Debian handles this well.

Get a distro with atomic updates, preferably an immutable one like Aurora[1]. Updates are automated and can't break your system. And in the rare event something does happen, you can easily boot the previous version right from the boot menu, no need for any scary commands or technical intervention.

[1] https://getaurora.dev/

"automate updates"

A device can be woken up at silly o'clock and "apt update && apt upgrade && apt autoremove && shutdown -r now" can be run via cron.

apt as deployed by Debian itself has options for automatic updates (via cron), which is the better option. Have a look under /etc/apt/apt.conf.d/

I was thinking about setting up a package as part of the system build to do remote maintenance and I wondered if manually doing those updates every six months would be too long of a window. That way if something breaks, I can visit the customers location to fix it if I have to.

upgrade and autoremove can be combined in one command. My usual line is:

  apt full-upgrade -V --auto-remove --purge

-V is just for verbose old/new version info.

> A device can be woken up at silly o'clock

It can't. The device is in my room and making noise when on. If that device wakes up and wakes me up, it's either getting a force shutdown (breaking the update) or getting in the trash. Plus the device is generally left in suspend mode, so shutting it down would interrupt my workflow.

Updates on Linux distros are not really a problem. You can work the whole time and just run updates in the background. You can even switch to a newer Linux kernel, without closing any userspace programs.

Mint's Update Manager has automatic updates built in. Go to Edit > Preferences > Automation.

Mint still being on Xorg sounds like a rough ride when it inevitably goes to Wayland, which seems to be the more common default elsewhere.