As a former Nordic patroller I can say MNS is correct. You never know when that "unused" equipment will be life-saving equipment for you or someone else

In winter it is common sense and common practice to carry at least mitten shells, if not complete mittens. The balaclave can and should be used when sleeping as well as backup headgear. And a vest of some sort is always a wise added "safety" item to carry in winter, whether dayhiking/skiing or camping.

Eric