First of all, the cover was received sooner than expected! I ordered the telephoto version which is long enough to cover my Tamron 150-600 fully extended. I used the small cover for 2 hours while taking photos at a ski race in 10F weather. I wore thin liner gloves inside the small cover and had no problems with cold hands or fingers. The plastic window did fog up which tells me my hands were producing heat. I was using a 70-200 F4 lens which just for inside the cover. The only issue was reaching the zoom ring. Making the left side longer and with more volume would make using the zoom ring easier. I also did not receive the storage bag. I think it worked well for the first time out. Subzero temps will give it a good test.
