Regarding the OnXmaps and cell service, you need to download the map to the phone or iPad for your hunt. When you do that you'll have the map and can turn off cellular that will run down your battery in no time and just use the GPS function on the phone.
As for all the landowner, outfitter, public land hassles or alleged hassles, there's so much public land in Wyoming that there's almost no reason to run into this as long as you're respectful, have some good maps, do some good research and if possible get the OnXmaps chip for your GPS.
My experience as a non-res hunter in Wyoming has been amazingly positive and given the chance the locals have helped me hunt there far more so than any other state including my own state of Nevada. The first time I went there four years ago I knew no one and now I have some great hunting partners and friends. The people of Wyoming are good people just don't go there and be "that kind of hunter" none of us like.
Robert