In my area of southern, rural Ohio, I get ATT clear as can be. Verizon works on one side of my house and doesn’t on the other.
I also think your idea of counter-balancing their position with your donations IS an acceptable way of dealing with these companies. Most of us think of switching, but I agree that phone reception is a different issue, since I have the same problem, only reversed.
So, what can you do?
1. Switch to a different company.
2. If one of these companies is your only option, then counter their position with a donation to a pro-gun group.
Makes sense to me.