Carhartts are just plain cold! They wear like rhino skin but they are not warm at all..... even my "Arctic" version jacket! When I was a lineman, winter punished me in those things until I turned to man-made materials. The man-mades will tear easier but they are light and darn warm! The trick was to get a thin "synthetic" jacket as a liner and then put the Carhartt over it for the abuse and abrasion.
As for boots, anything with gore-tex or the like and Thinsulate! Lightweight, warm, and agile to walk in. Canadian style packs boots are clumsy, cold, and heavy. Polypropylene underwear is good too!