With winter coming and my husband’s love of the cold I know I’m going to end up with windows open and buried under 80 blankets every night.  My sister was the same way when we shared a room in our childhood but she offered to leave the window half closed.  Now I don’t know if you’ve ever compared sleeping through the winter with the windows half closed and the windows open completely, but I can testify that there’s no real difference.  Either way you ‘ll find yourself begging for an electric blanket.  At least with my husband I can suck him dry for body warmth  – something that would have been might awkward with my sister.