Who makes a wool top capable of keeping you warm in frigid temperatures without space age insulation over the top? I expect it will be Merino wool, but are there any wool tops that teamed with a base layer underneath capable of keeping you warm on late season hunts? I've been wearing hunting clothes for so long that use man-made insulation I'm wondering how good old wool stacks up to them. I know it better retains insulation ability when damp, but what about cold and dry?