If your thinking about getting a new cell phone get a smart phone, the free Google Maps app is the best thing since sliced bread.
No more paying for yearly map upgrades, get true real-time traffic reports for no cost, all the same features as the typical Garmin. Went on a month and half cross country trip and NEVER lost cell map coverage using Verizon. Maybe once, at the bottom of Palo Duro Canyon
Google Maps are updated daily! at n/c.
Granted there is no RV specific info in Google Maps (for now) but we augment it with The Next Exit book.
By the way if you own any Garmin stock sell it, even their aviation, marine and cross country devices are not keeping up with losses of their auto division.
Ron W.