Im looking at buying my first quilt instead of a mummy bag. Im trying to get something that will work year around, instead of multiple bags. Im in Oregon, 80% of my hunting is early season archery. But i want to be able to be comfortable in temps into the 20's. Do i need a 0* quilt or can i get away with a 20* setup? The difference between 0 and 20 is significant. Thanks