I agree quilting has really changed from the time when quilts were made because of the necessity of keeping warm. Any scrap of fabric, even the less worn out sections of clothing, was used. And, some of those quilts are now in museums! So, I think, IMVHO, that you can piece scraps in any shape, with whatever seam allowance you'd like and make a nice and usable quilt that you can cuddle under. It may not win any blue ribbons, but it certainly will show creativity and love.