I want to hear more about Mint's coverage, I have straight talk right now. Do you have a smart phone? When you say rural what do you mean? We drive through a few states every year and I'm wondering if you can confirm where the dead spots are. Does it impact nav on a smart phone?
I do have a smart phone. It's the T-Mobile network, and there is broad coverage in most highway areas of the U.S. So if you are sticking to interstates, no problem.
Where I have had problems is on minor roads in places that are pretty sparsely populated. So for example, driving between Rockford and Galena, Illinois, my coverage dropped out a few times. And when we went to the very tip of Door County, Wisconsin, we didn't have any meaningful data coverage north of Ellison Bay. I mostly still had cellular phone coverage but even that dropped out when we got to the tip of the peninsula.
It does affect Google Maps if you need to load directions when you are offline, but it does not affect navigation that has already been loaded. There is also an easy way around it, which is to load offline maps for the area you are going to. And my $15 backup system is a U.S. atlas in the trunk. Once back when we still had Verizon, we were in rural Ohio and our directions completely dropped out due to cellular coverage and we had no backup - lesson learned!
To me it is well worth saving upwards of $50/month for the occasional inconvenience of losing cellular coverage. I'm old enough to have traveled widely before cell phones were common, so it clearly can be done.