If this was really the key...
to A's sleeping success then I will squarely kick myself for shivering all winter. Day two of the A in cotton jammies was even more successful than day one. She slept. Through the night. 8pm to 6:30 am. Did you read that? Just to make sure you did the math right, that's ten and a half hours of sleep. In a row. Well worth kicking the heat up a few degrees at night when the cold inevitably returns next week.
Phantom, if you haven't already done so, may I recommend that you get yourself to Old Navy or Carters or where ever and pick up some cheap cotton jammies? It's worth a shot. I'm still not totally convinced that this isn't just a fluke, but if this trend continues, Gina, I'll be calling on you to solve all my intractable parenting dilemmas...