These pants are nice and warm... much thicker than my Duofold varitherm midweights I purchased several years ago.  The downfall is the sizing - I am 5"7 105 lbs and bought the medium only because the small was not in stock and we had very cold weather on the way.  Thank goodness I did - even the mediums were too tight in the waist for my liking.  They do come up all the way to your natural waist (which is good for warmth), but I had to fold them down so they weren't constricting me around the waist.  Folding the waist works, but it doesn't stay put all that well.  They were a little baggy through the thigh (I have skinny legs), but not terrible.  I washed and dried on warm and they shrunk in length - to the point where any shorter would be too short.

Long story short - size up at LEAST one size unless constriction around the waist doesn't bother you.
Make a more comfortable and size-accurate waist, Duofold, and I'd live in these things!