Hiya Treesuit well I only found out about the B ration allocation a few weeks ago, on the QM website in an article called Food Service, Korea. They were really switched on about the weather conditions, and it takes up a lot of clothing QM discussion of the time. They were into multi layered clothing, the US army was really insistent on that method. Also trench foot and foot care.
I think it must have come from experiences in WW2 in Italy and the Ardennes, just as you say.
The only 1950 cold weather ration I can find is this Ration, Individual, trail, frigid, that I thought Hagens pack was. Wrong!
This was designed for small groups, patrols, and each ration weighed 3lbs. It came in 3 meal units.
It had dehydrated meat and cereal bars, cookies, crackers, nuts and raisins, chocolate, hard candy and gum and lots of beverages. It gave 4500 cal minimum. Its like the direct ancestor of the RCW or getting closer to the LRP ration concept.
It seems really advanced for the late 40s.