A quilt of flannel and minky will be warm. Probably warm enough for most housing situations. I don't think it'll need batting for warmth. If you want puffy, I'd recommend a wool batt. Because the fiber content of the three layers are very different and different properties, a wool batt will be warm. Maybe it could be made like a duvey (sp) and it could be filled with a down comforter and no quilting stitches.