Pretty sure the hitch height would be the same loaded or unloaded? You should have a weight distribution hitch install or do it yourself. This will keep your ride level stable. The ball height is fully adjustable so no worries about that. What's important however is the weight at the hitch when fully loaded taking into consideration propane tanks, batteries, cargo and any weight behind your tow vehicles wheels. This will ensure the proper rated hitch is installed. Maybe you know all this already...if not U-tube/Goggle is a fantastic tool...maybe you knew that also
Happy Safe Camping