My creativity has failed me. It turned out that I still had the better part of a skein of the Nashua left, so I decided to just frog the hat, pick up the stitches, and reknit down. After picking up the stitches, I felt-spliced the yarn until I got to the same color that the skein started with. Then I did a purl row because I always pick up the yarn wrong, and rather than have it look weird on accident, it looks different on purpose. I did another purl row a few rows down for the same reason. The cast off edge is a lot tighter than it was when it was a cast-on edge. But it still fits.
One of Sally's few redeeming qualities is that she doesn't really care about my knitting. When I wind yarn into balls she gets interested in the yarn spinning around... but other than that she leaves my yarn alone. She even tolerates being a model for my knitting!