Even then, that doesn't resolve the power outage primarily because the local nodes that your Modem transmits to will also be down in the area from same said power outage, most only have backup power for 10-30m, if even that many say there is no backup power for those which is why they disclaim that in their service agreement with regards to emergency phone calling over voip (for services that include unified communications).

So even if your local node could transmit, none of the others could, and they can't buffer either.

To mitigate power outage, you would need both power, and a cellular connection, and that connection would only be good for 2-3 hours (Cell tower backups), and those would require a Cradlepoint.