When that happened to me, I just made my binding a little wider and everything turned out great.

Congratulations on finishing your quilt. I have one that has been hanging around longer than I want to admit. I's near the finish line but I have come to hate the color of the fabric so I continue to put off working on it.

Lots of good ideas here. I would take the easy way out and trim it and the opposite end the same amount. Good luck with the method you use.

For all of my quilts, the batting and backing is 6" larger than the top.

For future reference, that happened because as you roll up the quilted parts of the quilt onto the takeup bar, the backing gets used up/rolled up more than the top of the quilt. Not a lot, but enough to make a difference when you get to the end, especially if it's a long quilt. Think of rolling up a magazine with the spine in the center, and how the page edges don't line up---the page farthest from the center is the "shortest", when in reality they are all the same size. You just need to allow more length in your backing than you did in this case. This has happened to me once, too--one of those lessons you only need to learn ONCE, lol. Congratulations on fishing your quilt!

This would be my choice as well.