Originally Posted by LovinMySoldier
I wouldn't bother cutting the extra off if you don't need too. Just piece the two pieces together and then when you sandwich your quilt together you can just trim it up closer to your top.
That's probably how I'd do it. Unless there was a LOT of extra fabric which might make it harder to quilt (trying to shuffle around extra backing) - but if it's not that much bigger, it'd be ten times easier to quilt and then trim.