I only did a quick peak under this morning and didn't see a dead pile. There were some dead bees by the entrance. I was going to install the metal cover when I got home this evening and can take a peak. I really didn't think about using a mirror for a closer look. THANK YOU!Moisture is a bigger threat by far than drafts. Bees ball up during cold. They flex their flight muscles repeatedly to generate heat. As the outside of the ball cools, they rotate inward to warm back up. Wash rinse repeat until it warms up.
As long as they have stores, I’m 99% positive they are fine. Use a mirror and look up through the screen bottom. If there’s dead piled on the floor, they may have succumbed. If there’s 30-50, they’re fine. Just too cold for housekeeping.