My Itasca is a different model than the one in your first photo above and has more ground clearance ... plus I have installed larger diameter tires than stock to give it even more ground clearance.
My Itasca has years ago done with it's then stock tires what your third photo above shows an RV doing:

What I don't have is 4WD, an overly-narrow width, and an interior height too low for my 6'2" height ... so we have to explore off-highway in dry weather and away from close rocks and/or close large tree limbs. Our rear overhang is not excessive and starts sloping up immediately from the rear wheels - unlike most Class C rigs' rear overhangs. With deep washouts, we go slow and at an angle across them. The V10 with it's 4:56 differential can handle long, slow crawls just fine.
From what I've seen of some of the AU desert outback in documentaries, we could carefully travel some of it with our good old Ford chassis carrying it's small underweight coach. It would just take the will to do so.