Lightweight clothing and winter don't mix well.

But here are my suggestions:

1. PacLite GTX shells are as light as you can get and have great wind protection (unless, of course you can afford eVent gear) Nylon windbreaker outfits are fine as long as the weather is not wet.

2. synthetic long johns are generally lighter FOR THE WARMTH than any wool undies

3. TWO layers of thin poly sock liners are better under a medium insulating sock than using one heavy sock

4. fleece neck gaiters are worth every ounce and nice for sleeping.

5. pile insulation dries fast but it's heavy for the warmth. Synthetic quilted or edge stabilized insulation like Thinsulate, Climashield, Primaloft or, my favorite, Thermolite, are much warmer for the weight and pack smaller.

6. Good luck finding warm but light winter boots. I doubt they exist.
For overnight camping you need a VBL to keep the insulation dry or you WILL have dangerously cold feet after the 1st day. Thin neoprene dive socks are very good. over poly liners. Then you can forget insulating socks as the neoprene is very warm inside insulated boots like felt pacs. But don't forget to turn the VBL neoprene sox inside out at night to dry. & take a fresh pair of poly liner sox for EACH day. Told ya, winter means "lightweight" takes a back seat.

And don't forget to take your insulating liners in your sleeping bag at night. You'll bless yourself in the frigid morning when you put on warm liners.

Eric