Sarabela ... if you like the weight, and want a really warm quilt - you might want to think about two layers of W&N. But if there will be more than one quilt, perhaps wool is a good bet, with another quilt batted with W&N.
I'm like you, I sleep with the window open a bit even in the winter. I like the room cold (fifties) and I would rather throw another quilt on the bed to keep warm but have the room cool and fresh air circulating.