For temps that get realy cold (sub zero) I would suggest you look into either Sitka Gear Fanatic bibs or Sitka Gear Incinerator bibs. With proper layering of each, they could both work. The Incinerators will take your comfort to a lower temperature, but he Fanatic will give you a wider range in utility. However, if there is no property void of burrs or stick-tights, then the Incinerator may have the advantage. The 2015 version of Fantatic has a berber fleece outer and utilizes windstoper. These are based on my own opinion. Good luck with your search. Mike