moosh (cli only) has a restore command.
Restore course from path/to/backup.mbz to category or existig course.
Example 1: Restore backup.mbz into category with id=1
moosh course-restore backup.mbz 1
Example 2: Restore backup.mbz into existing course with id=3
moosh course-restore -e backup.mbz 3
one could create a looping bash shell script for the changing course ID numbers and get a lot done in a short time frame ... that's after testing one or two restores to see if it 'fits'.