By the way, regarding 2X4 versus 4X4 when offroad in a small Class A/B+/C rig:
Note that these type RVs will have an awful lot of weight on the rear wheels ... probably more weight than what's usually on the drive wheels of truck camper pickups, 5th wheel towing pickups, and trailer towing vehicles. For this reason a heavy on the rear 2X4 and 4X4 small Class A/B+/C motorhome may have an advantage over both 2X4 and 4X4 truck camper pickups, 5th wheel towing pickups, and trailer towing vehicles. This superb rear drive wheel traction due to a large amount of weight will also help to make small any advantage that a 4X4 small Class A/B+/C has over a 2X4 small Class A/B+/C.
Of course in real soft stuff this could make you sink fast in the rear, too ... so in these situations driven front wheels would be more of an, and maybe a critical, advantage.