When I have done a quilt with pieces or blocks that were too small, if they were just a little too small, I'd use them anyway. Like if they were off by 1/8" I'd mark one edge with a pin, then when I was ready to sew that seam, I'd pin it to the next piece with the edge just "off" from the other piece. As long as you have at least 1/8" of fabric in the seam, it will be fine. Or if you have more than you need, cut them to 4 1/2" and set the small ones aside for another project, either a small wall hanging or pillow.