I have two Moodle servers, A and B. Actually, production server 2017 and production server 2018.
Several times a month I download a 2017 course to my desktop and restore it to the 2018 server. It takes just a few minutes. Would that not work? Unless your teachers do not have rights to download and restore, it should be easy.
By the way, the Moodle Association of Japan is making simple Hub plugins to replace the old Hub code that ended in Moodle 3.4. That is while we wait for MoodleNet. Hopefully MoodleNet will come in a year or so.