You would be better off with a system approach. From base layer to top layer based on temp and your activity level. Cold Gear would be fine if you had on an outer layer of wool on.
These base layers are designed to control your skin moisture level not insulate! Poly products evaporate moisture quickly to keep you dry when it is cold, a back full of sweat with a t shirt on in sub 32 deg temps will not keep you warm, but a poly shirt that dries up quickly after you sweat will keep you from freezing. That is the base layer. Your insulation goes on the outside to keep you, on the inside, regulated. Poly, fleece, poly fleece, polypropylene, gore tex, supplex, etc etc. are not insulators they are loft, and water/wind barriers, wear lots of it and you will trap air inside the layers and keep warm, or just wear real insulation, like wool, and keep warm.
Stand hunting on a cold day: expedition weight poly long johns next to skin, 27oz wool pants, shirt, hat, add a vest or jacket if it is windy, or, really cold around 15deg or so. Wool longjohns if you are stationary all day is fine, but if you are walking around, hiking in and out, the poly products will evaporate your sweat much faster then the wool longjohns.