My coach is equipped with a Hadley Air Leveling system. I can raise it by 6 inches to clear bumps and dips or I can lower it by 6 inches to clear tree limbs or other overhead obstructions. It can only be adjusted while traveling at slow speeds (under 10 MPH)
The ground clearance on my coach varies depending on how close a component is to an axle. For example, the differential is about 5 inches off the ground but since it's between the tires, it's unlikely to hit anything. The average ground clearance ranges from 8-10 inches, but things get interesting around the margins.
My mud guard is only about one inch off the ground and I'm always concerned about my tail pipes.
Dips and curves present special problems and the length of your wheelbase and overall length will come into play here. For example, a long coach with a short wheelbase would have no problems with hills, but would have major problems with dips. Conversely, a short coach with a long wheelbase would have few problems with dips but could have problems with hills.
If it's only your driveway you are concerned about, don't sweat it. As someone mentioned above, you can always adjust with grading, blocks, or planks of wood.