Seems like a great reuse for a new selfhost style community using lemmy/kbin. How much are you asking for it, or willing to part for it?

Take a look at these guides. They explain a lot as well about Kbin

https://kilioa.org/m/kbinfaqs/t/725

https://kilioa.org/m/kbinfaqs/t/1336

For basic word processing and excel like items I’ve used it and recommend it for others. Especially when I’m on my Linux desktop. I’ve used it for some small businesses as well so they could open and send files for work.

ZeroTier is great! There’s another one out there I know of that haven’t used.