I just used my new set of 0 degree UGQ topquilt and underquilt at a not very cold hang. It was very toasty and definitely overkill for 20 degrees, windy, and humid (freezing rain then snowing). I'm expecting to get a 40 degree set soon. I'm wondering how you decide on your insulation to bring on a particular hang based on the forecast. Err on the side of warmth?