Our overhead door is an honest 10 feet and we have a few inches clearance with a flat approach so the rear trailer upper edge is not artificially elevated. Our side walls are 12 feet so there’s adequate clearance to lay out over the 21 for maintenance caulking and waxing without the trusses getting in the way. I use the 21’Little Giant ladder rated for 350lbs and my wife says it’s real stable for her too. We have the standard 15 inch wheels, no lift kit, 2013 E21 Classic. The building is 24 feet by 32 feet so there’s room to deploy and raise the awning if it’s wet when we come home. The dead flat reinforced concrete floor and vermin proofed wall to floor interface keeps the Escape clean and without vermin worries. Door is 18 feet wide. My brother wired in a 30 amp outlet from my 150 panel in my adjacent shop building. This allows working in the Escape on hot days running air, and to precool the refrigerator on electric. I have fresh water about 60 feet away so filling the fresh water and water heater are easy. I have my 16 foot boat and trailer across the back of the building and my turf equipment in the second stall.
Hope this helps
Strike while the iron is hot. Live every day as if it were your last and one day you will be right.