I have a pair of the lightweight Montbell down pants too and they are cozy. To tell the truth their ultralight down vest is the most useful insulation in my kit, easy to pack and keeps the core warm on blustery days when stopped. Pair it with a lightweight windbreaker and that’s about all we need in the lower canyons. I have thrown in the jacket and pants for higher elevations in colder months but barely use them. Good backup if needed though.