My grandmother made her "hunting" quilts from wool scraps with cotton batting. I don't think she had lots of options though.

Since I'm in Texas, I don't generally want a warm quilt (I'd just put an extra on the bed if it was really cold). I would think that a poly batting would be the warmest.

bkay

I would look at the variety of wool batting available.

Wool would be very warm.

I'd recommend wool batting and to make it even warmer you could use flannel for backing.