Puff quilts are very warm!
The way I make them is to stitch in the ditch long "tubes" (4 1/4 inch squares finished), then stitch one ditch across the middle, then stuff from the ends a handful of polyfil. (push up w/ yardstick). Seal off each square puff a row at a time...When you finish it is puffy and warm!
Another idea to make a warm quilt is to use an old pattress pad as batting -- these are actually heavy enough to use as beach blankets or "moving" blankets! (protect furniture) if you use scrappies.