Just read a more interesting blog post than this will be. I recommend you check it out. Posting here for my reference.
https://staltz.com/an-off-grid-social-network.html
Here's a link directly to the project: https://www.scuttlebutt.nz
I've often thought about this, but there's a huge difference between thinking and doing. I'm glad there are doers out there!
Can't wait to dig into this. I'll write a follow up post if I come up with anything interesting to say.