A couple of simple suggestions… I did not know this for a long time, but the Google Maps app allows your to download very large sections of the map for offline use. Worked great for us for multiple cross country road trips. You don’t have to rely on service for accurate navigation. As for comms, we have a Garmen In Reach GPS/satellite device for backpacking. You can send messages and texts plus there is an SOS button if you get in a jam.