Hey, River Hill... I've learned over the years that the most important cold weather items are boots, gloves and head cover. If your budget is limited, I recommend you devote the lion's share of it to those items. Get good stuff. Especially the boots and gloves. Pay attention to the ratings system used to rate the boots...know the temperature ranges you expect to hunt in..some boots are for keeping you warm during mild activity (like walking) but will do you NO good while sitting still in a stand. My hunting comfort improved 1000% once I figured this out. I also bought good, insulated coveralls that are a size too large. In mild weather I can wear just the coverall...when its cold, I have room to wear it over layers of non-camo clothing. That way I dont have to invest tons of money into big piles of camo I only need a few times per year. When I get warm, all I have to do is take off the coveralls, shed some layers, and put the coveralls back on. I also keep a few of the chemical Hot Hands in my pockets for emergencies. We dont have extended periods of cold here like you do up north, but we have "cold snaps" for a few days here and there. I hunted all day out in 17 degree temps a couple of seasons ago and I was plenty comfortable.
Good luck