eparys

I use W&N (I have two bolts of it - one Warm and White and one Warm and Naturel)- it will not fluff up but it is warm an toasty in a quilt. IMHO, a double layer might be too heavy in weight - a single layer Queen size quilt is heavy as a whole quilt - but not heavy to sleep under. I would be concerned that with two layers of W&N it would be too heavy to sleep under.

I too live in the snowy north and we currently have one blanket and a quilt with one layer of W&N in it - and both the DH and I are very comfy with it. Loft does not always equal warmth. The first quilt I made was for the DS and had it quilted - the quilter used a lofty polyester batting - looked cuddly and beautiful but turned out that it was not warm at all. He now only uses it in the summer as a bedspread.

If you want the "puffy look" I might think about laying a thin layer of the poly batting over the W&N - it will add the loft with out the weight. Another option is Wool batting or even Bamboo Batting - I recently used those is a few Baby Quilts - they seemed a bit more fluffy and quilted beautifully.

You could also use flannel for a backing - this would add warmth without a lot of weight.