There are stories of people adjusting the door. I have not had to so not sure how. As far as insulation are you talking about putting more insulation in the door or around it? I figure the ramp door is probably the highest quality part of the trailer as it has to support heavy vehicles being driven in and out, plus serves as a patio deck too—I can’t imagine opening up that door. Besides the garage area itself has less HVAC vents than the rest of the trailer so always seems to be hotter and colder than elsewhere so not sure what you would gain by just working on the door.
You are probably right. The entire living area of my Triton 2951 is garage, so the main table/seating is the Happi Jac bench seat at the rear, right next to the loading door. The door itself is quite cold to the touch, and there are some air gaps where the door doesn't quite seal. Last year, I hung a cheap quilt with screws around the frame of the door and that helped some. I was just wondering what others have done.
My rear door closes tight on one side, but has a small gap on the other side. When camping in SoCal deserts it gets pretty windy so I try to park away from the direction of the wind. You can adjust the top latches somewhat. As trying to make the garage a comfort zone, forget it. I have portable heater and a.c. unit to help make the area comfortable. Voltages idea of a zero ramp door using a electronic latching mechanism is for the birds. I might later down the road install mechanical latches that draw the door tight to the frame and existing seal.