Very interesting. We were discussing stuff like this (not perse blockchain, but could be a good backbone) due to the recent power outage in Amsterdam. I discussed with a guy from 'the things network' how we could run an emergency internet / comm's platform in case of power outage.

The 'Things Network' is a LORAWAN (Low Power Wide Area Network) implementer. However the LoraWan spec (I think) cannot be used for blockchain transmission, as it is a shared transmission network where individual nodes get a certain timeslot assign to broadcast their packet, which get redistributed through the independent mesh network.

Also, the devices by Things Network are currently only online for an additional half hour after a power outage, which should be increased.

The Kryptoradio initiative indeed looks very cool :)