Stuck upgrading older install

[freedomlives]

I have an A20 which is on Ubuntu 18.04.6 LTS bionic. It is sitting at my mom's house (which is on a different continent). As I logged into it today to change some things, first thought was to update it. However, the upgrade fails as packages from the olimex server are no longer available (e.g. http://repository.olimex.com/pool/main/l/linux-bionic-root-next-olinuxino-a20/linux-bionic-root-next-olinuxino-a20_5.92.4_armhf.deb )
As I won't have physical access to the board until the next time I visit my mom, which would be months from now, what are my options for fixing the problem?

[LubOlimex]

I guess this is older image that is no longer compatible with our packages. The best idea is either use the image without changes or write a new SD card with the base image here:

https://images.olimex.com/release/a20/

[freedomlives]

I guess making a new SD card, configuring, and then giving to my mom when she visits to swap out could work. That much she can handle. I've read now that you only have Debian at this point, so will have to abandon Ubuntu.
I have an A20 over here as well, so I can test that the image works beforehand.