For my part, I prefer NixOS, too, and it works just fine on a laptop. However: do-release-upgrade is really conservative about shutting everything down and rev

For my part, I prefer NixOS, too, and it works just fine on a laptop. However: do-release-upgrade is really conservative about shutting everything down and reversing as much as possible if anything goes wrong. But if you know your way around apt and dpkg and you know how to mount a borked system and chroot it, you don't really need do-release-upgrade. Just manually hack up your apt sources to the next LTS release and use your favorite apt frontend (aptitude is probably best for this) to upgrade and full-upgrade your way through it. Use dpkg with some --force flags if the state of things gets really messed up.