Thus, we have the general population relying on cellphones for their voice and text communications. Those devices, besides needing to be charged, are only as good as the cell towers that they communicate with.
See this article on the situation that has been experienced in the California Fires and is easily replicated in any earthquake situation, Cellphone Outages During Fires Preview Life After a Big Quake.
A quote from the article highlights the fact that redundancy in power for wireless company cell towers is not a given, "There are no federal or state regulations that mandate cell carriers have any backup power for cell service, said Ana Maria Johnson, program manager with the Public Advocates Office, an independent organization of the California Public Utilities Commission that advocates on behalf of consumers."
The above provides an excellent question to ask of your local wireless service providers.
And will FirstNet give you a better "power" capability via their infrastructure — since their network is supposed to be hardened to a degree beyond commercial standards?