Your crib quilt is darling! I am just finishing the top for a crib quilt for my first grandbaby, too, and have pondered the backing question. I am backing it with flannel and didn't realize their could be oh so many ways to piece it together! LOL If I had it to do over again (the flannel is already purchased), I would have just purchased a flat twin sheet. It would be wide enough and no seams would be needed. I think it would work okay???? Have a good trip and kiss that new baby for me!