This sounds over-engineered. Why not just setup something the user can leave connected to their home Internet connection and do the backups through there? In an

This sounds over-engineered. Why not just setup something the user can leave connected to their home Internet connection and do the backups through there? In an emergency the user could simply drive home to get it. If you’re already thinking SSD, it’s probably not that much data. Then they don’t need to do anything other than set it up once. I think your plan of having them transport it to the office once a week has the same flaw you already mentioned (any effort needed on their part and it doesn’t happen). And if they don’t have to transport it, you can use an HDD and get a lot more space. Syncthing could handle the syncing.