This bag is ridiculously warm...and that says a lot coming from a girl who is always cold! I took this bag up Kilimanjaro with me and had to sleep with it unzipped every night until it got below freezing. I'm 5'10" and have a regular size bag which was plenty to put pretty much all my clothes in. My only two complaints were 1. I was so warm that I woke up every morning with mad amounts of condensation on the top of the bag, it would be soaked. I'd dry it the best I could, pack it away and then lay it in the sun the next camp we got to. 2. There is so much loft around the shoulders and neck that the zipper got stuck for me a lot. It was fine if you were paying attention...but when you are groggy at 2am and trying to get out to use the bathroom, it was easy to get stuck!
When it got into the single digits at night I would put a hand warmer in the bag by my feet and they stayed nice and toasty...no bag on the planet would keep my feet warm without it!