If a wool cap is a given, then I would bring my GI wooley pulley or Baja jacket, since I always carry leather gloves with me.

Personally speaking, I don't have much of a problem keeping my legs warm if I can keep my body trunk warm.

Long Johns give me winter skin and I need what's left of my mind, undistracted by itching.

Keep in mind, my cold weather experience comes from icebreaking, which is a different world from camping out in the mountains!