An update to the update:
The swatches have relaxed overnight, more than I have, I might add. The last swatch on size 6 needles is too small. The one on size 7s is now just about right. It's off by a hair. I need size 6.9 needles, I guess. I'm going to go forward today and cast on with the 7s. Let's hope that the knitting gods are with me!