Gotcha, When I lived in AZ the farthest I pretty much would get is a few trips to Puerto Peñasco, I love that place in the off season.
For the handhelds I would suggest picking up some cheap mag mounts like this https://www.amazon.com/Boblov-UT-108UV-Magnetic-Antenna-Booster/dp/B01FVR209A/ref=sr_1_6?ie=UTF8&qid=1475682099&sr=8-6&keywords=2+meter+magnetic+antenna
They tend to have a hard time getting single outside of the vehicle, all that metal acts as a faraday cage, and this will greatly increase the range.
Also if they're Baofeng, to save on battery you could get something like this