If I'm throwing in my .02, I'd probably recommend a cam buckle style strap, or even some 1" ratchet straps to cinch it down. My main concern with the hook and loop would be if they got wet, they may freeze and render it ineffective.
Also, you may want to check out the Otter bags. I have a Resort and one strap in the middle is normally all it takes to fit it in the bag. They are very generous on the size. I fit my shanty, all the anchors, Milwaukee drill and a few batteries, and my puzzle piece flooring mats in the bag. The bag zips all the way down the side. I have no idea how much they cost to buy seperately, but I can't imagine it's a lot. If they are more than $40, I probably wouldn't buy one, but less than that, I think you'd be happy.