Last winter, we did not have much of a winter in Michigan. (Global warming?) But, there were days when the temp dipped way below zero with a fierce wind. On those days, I wore my Mil-Spec coat with just a shirt (no sweater) and was warm as toast. It is, after all, 32 oz wool--a heavy coat.
I like the lining in the current issue (Mil Spec for civilians) better than the lining in the vintage models. It is a softer lining and traps body heat better than the "hard" rayon lining in the vintage models. Wearing a sweater, however, pretty much makes moot the difference between hard and soft linings. As CP notes, a sweater might not even be necesarry with a snuggly fitted curent issue (Mil Spec) peacoat. Remember, the less air flow around the body, the warmer the coat. The more body heat trapped by the lining, also makes for a warmer coat.
fyi for anyone looking to buy Schott, you may want to consider sizing down two sizes. I normally wear a 38 jacket, but 36 was still too big on me and so I'm awaiting a 34 - hopefully should be right. The p2p for 38 was 23", 36 is 22" and 34 is 21" ...Unfortunately I got the measurements for the 36 and 34 after ordering the 36.
Those are really huge pit to pits for the stated coat size. It is a good example of why the manufacturer's stated chest size should never be relied on. Even the issue peacoats have variations in the p2p within stated chest sizes. A difference of 3/4" in the p2p will mean a difference of 1 1/2" in the chest size. This can mean a difference between a well fitted peacoat and one that is either oversized or too tight for comfort.
After sizing down two sizes, I wonder how well the other parts of the coat will fit, such as the sleeves, shoulders and torso length?