Hell yes! This is what I did at Ericsson.
1. Cell phone towers can be redundant, independently powered, and well protected (as long as the protection does not interfere with radio signals.) The link to the "network" does not need to be a wire, it can be a microwave link to another terrestrial site, or to a satellite.
2. We keep saying: keep cell phone towers in reserve (in large office buildings) with their own power supplies so they can be (literally) rolled out, connected to its other parts, and started up after an emergency. This is unpopular with the major telcos, since it costs money.
3. We pioneered the 8-hour/24-hour install at Ericsson many years ago. We would get notice 24 hours before a site was supposed to go live that such-and-such government wanted cell service at such-and-such location. We would strap the cell site to the bottom of a helicopter, and deliver it the next morning. 8 hours after the crate touched the ground, the cell site was active. It's nice to have a cable running somewhere, but more often than not, we depended on microwave links.
One more thing...and this is a FCC policy thing...We could create an "emergency" mode where a quad-band cell phone will talk to any network in range, and where the networks can even load balance between themselves (so no network goes "down.") We have the hardware, it would just be a software patch.