I bought a used APC Back-UPS Pro BR1500G for $100 on market place, it was a good deal, I replaced the 2 battery inside and added 4 outside (it is supported), I'm ready!
I sometimes have power outage in winter (snow storm, ice, etc) and working from home I need a UPS ; modem cable, router, PC, monitors, are on it, it can stand ~5h
Do you have GRUB? If yes you can edit your kernel command line and append "init=/bin/bash", see if at least this gives you a prompt, this has saved me a couple of time in the past. Else booting on a USB and mounting your boot partition may help to fix it.
BTW I also have LUKS and I'm using TPM, using tpm2-initramfs-tool, first, it failed because I forgot the tpm modules in initrd, but I always have 2 kernels installed and only modify one initrd at a time to have a safe boot if I have a problem, like I had!
I tested tpm2-initramfs-tool with proper tpm2 modules and it worked.
I also tested with clevis-initramfs and clevis-tpm2 and it's even easier, no messing with crypttab.
Also, as long as you can break GRUB and append "init=/bin/bash" it is not secure of course, you can then prevent grub editing or not using grub at all.
A couple of them have family there, or when you live 10 minutes to the border it is always tempting to fill your tank there for instance. Some have vacation planned for a year like Disneyworld or others. A lot are on business trip too.
Yes, based on one of the Robot story by Isaac Asimov, great series of books BTW, then read the Foundations book series, then watch the serie it's not bad.
Guys, it will never be done, especially in our lifetime. They are talking about it since the TGV exists in France, more than 40 years ago.
Just the Montreal-Ottawa corridor will cost 100 billions $. Forget it. If you want train go in Europe or Japan/china.