It is not difficult IF you know what you are doing!
Get a DeLorme Atlas and Gazetteer for the state in which you wish to boondock. These maps will give you an idea of where public land is. Remember, it is YOUR responsibility to know exactly where you are. You may NOT camp on private land without permission!
Also, be aware that in some areas "dispersed camping"; that is, camping outside campgrounds, is severely restricted. It is best to stop at the ranger station and see where you can camp, and get a map of the forest roads. Some roads will be closed. It seems there are more every year. Some of the places I used to camp are no longer accessible!
Personally, if I wanted to go to back country areas, I would not get a coach any larger than 36 feet long. In fact, my 32 footer is about as big as I want to take on some back country roads or into primitive campgrounds.
Watch out for low trees. The branches can do a lot of damage!