I just bought something like Under Armor, but a different brand from Fleet Farm. I also bought a set of Wickers Thermal Underwear 100% Polyester Fleece. And a set of Rocky cold weather fleece top and pants underwear.
So if I use the Fleet Farm Under Armor first, and then 2 layers of Fleece underwear tops and bottoms over that, this should be a good base layer. And then add a pair of insulated pants and jacket. I should be toasty.

A big question I have is the Fleet Farm Under Armor type shirt cost about 36 dollars.This is the one that will touch your skin. I can't afford to buy one for each day. So do you wear yours over and over each day? Would it be ok to wear a t-shirt under this, that way I can change my t-shirt each day to prevent stink.Or does that defeat the purpose. What are you guys doing for this?
I am not worried about the scent free aspect of these clothes.