Probably a good idea to go see how much storage will be necessary...

https://slrpnk.net/post/28978076

I stumbled across this sort of fascinating area of doomsday prepping a few weeks back.

prepperpress.com/usb/

A nice addition to that, don’t just make it a USB, but a raspberry pi. So you’d have a reasonably low-powered computer you could easily take with you.

Not suggesting this one as it seems a bit expensive to me, but prepperdisk.com/…/prepper-disk-premium-over-512gb…

Build a Bug Out USB

A USB flash drive lets you carry mountains of survival information in a low cost, lightweight, compact device. Some preppers might criticize the idea because it requires an electronic device…

Prepper Press
Just built one ofthese myself. I went NVME M.2 instead of SD Card to avoid data corruption. I know SD Cards are fine if you don’t write to them a lot but if you wanna update or add your own stuff, scares me. Plus NVME is just so much faster.
How would you access the info if electricity permanently goes out?
Pretty much what Sinthesis said; USB power brick and/or solar panels. Both at the ready and tested. Also got a big ass battery backup that will charge off solar panels.