I looked at a BackFlip cover a few years ago for the F150 - they seemed pretty sturdy in the aftermarket shop demo. No idea how they do in -30C or with 2 feet of snow on them. Ended up getting a used Access roll-up soft cover instead (I believe the Lorado model?) from a guy in Michigan. It's been great - relatively easy to install, easy to open and seal, and no problems with warping/sagging when a load is placed on it.
I really like those hardcover roll up tonneaus, but man they're expensive and the hardware takes up quite a bit of room.