The easiest offsite backup would be any cloud platform. Downside is that you aren’t gonna own your own data like if you deployed your own system.

Next option is an external SSD that you leave at your work desk and take home once a week or so to update.

The most robust solution would be to find a friend or relative willing to let you set up a server in their house. Might need to cover part of their electric bill if your machine is hungry.

Even then, there’s a warning that the upgrade process can take several hours. Even if it’s largely hands off, that’s not exactly my image of an easy upgrade.

Specifically upgrading major versions. See the official documentation for upgrading Debian 11 to 12. It’s far more involved than minor version upgrades.

https://www.debian.org/releases/bookworm/amd64/release-notes/ch-upgrading.html

Here’s the official documentation for upgrading from Debian 11 to 12. The TL;DR is that it takes 8 chapters to describe the process.

https://www.debian.org/releases/bookworm/amd64/release-notes/ch-upgrading.html

The problem is when it comes time for a major version upgrade. Debian 12.10.0 to 12.11.0 probably won’t be a big deal. But upgrading from Debian 11 to 12 was a pain. Debian 12 to 13 will probably be a pain as well.

The thing with Debian is that yes, it’s the most stable distro family, but stable != “just works”, especially when talking about a PC and not a server (as a PC is more likely to need additional hardware drivers). Furthermore, when the time comes that you DO want to upgrade Debian to a newer version, it’s one of the more painful distros to do so.

I think fedora is a good compromise there. It’s unstable compared to RHEL, but it’s generally well-vetted and won’t cause a serious headache once every few years like Debian.