After living in Bremerton, WA and freezing all the first winter, I learned the value of a fleece coat. Fleece does not absorb water, wind doesn't go through it, and stays nice and toasty through the day outdoors. If I were making any kind of blanket to stay dry and warm, I would use fleece. Just remember to shake the water out of it before bringing it into the house. They do not absorb, but water does stand on it, so shake it off. If you make a custom size fleece blanket, with strategically placed snaps, and a built-in hood, you could watch a triple header staying nicely warm, and dry while doing it.