I've done some mesh networking (ham radio), and we actually had people connected when the Internet went down after a mudslide here (the Montecito mudflow).
I have a stash of mesh radios I have been meaning to reconfigure specifically do this post-disaster (on the project pile, LOL). That said, keeping those radios powered is HARD, and data connectivity is not necessary.
A bunch of people with handheld radios and AA batteries are going to be FAR more effective than any kind of mesh network and high tech anything (in my opinion, having been involved in post-hurricane response several times using radio). Because... KISS. Data networks are not easy and simple... handheld radios are.
Story from North Carolina:
https://www.wcnc.com/article/weather/hurricane/helene/ham-radio-helene-recovery-north-carolina/275-a905e9cd-5b86-48ff-b4b5-f0e4546115dd
