I borrowed a friend's Downmat for a trip to Mt. Whitney. The temps were near zero and the wind was 50 knots.
The Downmat was surprisingly warm. Part of the night, I slept under my sleeping bag instead of zipped inside it. I purchased my own Downmat after I returned from Whitney. It should serve me well in the future.
This review was written in the old system and had content requirements that are different than reviews written today.