It really makes me sad, jeeps used to be awesome till Chrysler started getting bought out, around 2000. It was like when the AMC 4.0 and the Chrysler 318 went, so went Jeep.
Yes, they are inefficient, and slow, that's not the point, you could offroad in a ZJ with 250k miles on it and be ok.
OK 80 GB is for sure an edge case. Nextcloud won't even work for that due to PHP memory limits, I think.
Interesting problem. FTP is an option, with careful instructions to an untutored user. Maybe rsync over a VPN connection if it is always the same sender.
Not even sure what else would reliably work, except Tannenbaum's Adage.
Sending is someone else's problem. They have all sorts of different understandings and tools and I can't deal with them all. So the only alternative is to set them up with an account in (e.g.) Nexcloud or just accept whatever Google service they use to send you a large file.
Sending other people files is easy in Nextcloud, just create a shared link and unshare when done. Set a password on the file itself.
It has always worked fine for me. The occasional upgrade process is manual but literally just a command.