Im not an expert so yeah grain of salt i guess. The major issue with Wifi networks is range from my experience. Houses visually close have barely showing wifi signal. How many of your neighbors have laptops and ways to run them for more then 2 hours on batt power? Also most people do not plug in laptops or desktops during storms for fear of frying them.

It is a good idea to start with before the hurricane hits but during the storm actually hitting it would become a moot point. Also i would simply suggest setting up a web server using a old computer with a linux distro made for the job and making it open to your neighborhood via a password handed out. I think that would be simpler and more reliable considering the limited and more complicated ways of setting up a network for your entire neighborhood.

Another idea would be getting everyone to purchase a 1 gig or so pen drive and getting it updated at meetings there for no reliance on internet.