by Ken Task.
For that to transpire as planned, wouldn't one have to un-hide any hidden course or set options for autobackups to include all courses (even hidden) and courses that have had no changes?
Agree with Emma that getting the backups out of the file system (course backup area) using the system is probably the safe route, but getting it to do it is a bit of a task (no pun intended) considering one needs to also empty the trash in a timely manner (a control un-found in the Moodle UI). Plan on a 4 day project as that's the default for empty of trash.
My 1.5 cents! ;)
'spirit of sharing', Ken