I was about to post the same thing! With my tonneau it's hard to say no, with a cap I can just ¯\_(ツ)_/¯ and say sorry!
My ice fishing sleds (yes plural, and no, not the kind with a motor) barely fit under the tonneau now. If I ever got a snowmobile/atv I'd put it on a trailer. I think the real barrier is just cost. If I used it to sleep in often enough it would be worth it. If not, maybe not.
A.R.E has a "build your own" app on their site (http://www.4are.com). I put in a request for quote for kicks. I'll share it when I get it from them.