3/8ths is pretty thick but you should still be able to heat once you get it dialed in. Those stickies will work decently...especially if you can get them for the middle of the cage as well. Also you can just type rubber feet into google and a bunch of them will come up. Some are a little more robust than others and will hold up the cage better than the little stickies that the heat pad came with. I would try this route first because it is easy and cheap...as far as living up the the canadian stereotype maybe get some mini hockey sticks for handles on the front plexiglass haha. Seriously though good luck and keep us posted if lowering it works. My vision cages are elevated and I had to put a piece of fiberglass under my UTH to stop heat from escaping and it worked quite well.