Good point but tbh I'd stick my TomTom Rider 400 motorcycle GPS on the windshield before I'd bother with downloading offline maps. There's just no substitute for a real GPS.Use Google Maps and download the area you plan on driving for offline use. Then no data connection while driving is no problem. Not as easy as using built in nav, but a decent workaround.
We're going to the Upper Peninsula next week. Almost guaranteed no cell signal up there. Downloaded pretty much the entire state of Michigan just in case.