That was quite a haul and you will love working with it--esp. during the winter months. Please make something and let us know how it goes. I'm not jealous --I am happy for you! I will admit that I love touching flannel though...
I'd be surprised that 100% cotton pills. I've been taught it is the polyester in a fabric that pills--all cotton doesn't. So, maybe if someone has cotton flannel that is pilling, maybe it is the batting that is coming through the middle! ?? I don't know--just a suggestion.