Here is my tried and tested sleep system for prolonged outings in the cold – particularly key when thereis not much sunshine to offer any kind of radiant drying inside the tent.Here are my layers from the inside out:
A reflective vapor barrier liner - Western Mountaineering
-15F PrimaLoft down blend inner bag
25F PrimaLoft synthetic over-bag

Get the synthetic bag slightly bigger then the down one.Ensure both bag zippers are on the same side.ScheduleSchedule