Good assortment of photos. Yep - your stuff goes outside the overcoat. A remember to loosen the straps on your knapsack. I remember getting numb fingers because the straps were too tight. Yes, your water and food will freeze if far enough from your body heat in cold enough weather, and I think that would have been considered an acceptable cost of soldiering in those days. At the same time, armies tried not to maneuver in the depth of winter, either, so you would be carrying your gear for at most a few hours while walking a guard post. I don't think a corporal of the guard would fault a soldier for carrying his canteen under his overcoat. Any evidence that soldiers carried a canteen of hot liquid (coffee or tea) snugged up under an overcoat, like a hot water bottle?
Pine River Boys, Co I, 7th Wisconsin
"We're... Christians, what read the Bible and foller what it says about lovin' your enemies and carin' for them what despitefully use you -- that is, after you've downed 'em good and hard."
-Si Klegg and His Pard Shorty