M.L.
I know a woman who took about 1 to 1 1/2 yard of fleece, cut them in about 7 inch squares or rectangles and that was plenty. No need for sewing or anything.
Not sure how many that turned out to be, but there it is. I've heard people say anything from 40 to 80, just think, that about half will always be in rotation and several will be in emergency places, like a stash in your car, purse...