I also buy more than I need because I learned the hard way not to assume the fabric will be there if you need more. I would rather than too much than not enough. Recently, I attended a Bonnie Hunter event. She has show and tell after lunch where attendees can show the quilts they finished or are working on. I was fascinated with the backs of some of those quilts. The quilters used extra blocks or extra fabric and designed beautiful backs for their quilts. You might want to think about that with some of your extra ... and make an interesting back for your quilt.