I have yet to test the bag in cold weather but my initial impressions are that the bag is very roomy, particularly in the shoulder area (I am 6'2" with broad shoulders and athletic build). Also, the pocket to fit in the sleep pad is great. I use a thermarest inflatable and also can fit in a open cell foam pad at the same time for extra comfort and insulation.
This review was written in the old system and had content requirements that are different than reviews written today.