I've thought about it but put it on the side burner after trying to figure out how to handle the door at the upper hinge line. If you left that area uninsulated, it would only be a couple of inches for that width. I'm not in a cold climate so it is a non starter, but for guys up north, I think it would be worth the job. Like I said in another post, you don't need thick metal covering the insulation, you can get by with some much thinner sheet. If you could wrap some notch cut angle around it, you could rivet aluminum sheet on, that is much easier to work with and you really don't have to do more than the top half and ends. The domes would just be a bitch...