Howdy, I am in Madison Wi, have one hive with 2 supers that started fall with about 90lbs honey, this is my first winter. I first noticed it on a sunny day, with temps only 35*F or so, I see about 50-75 or so bees were leaving the hive to void, but none made it back, leaving golden poop on the snow, with most of the bees frozen on the ground in the center of the poop. these bees were exiting the vent hole I have in the top super, but they were not leaving the front entrance of the hive, so I figure the bees are in the top super, and it was easier for them to leave from there. I have no question here, just observation,I figure that the bees had warmth in the hive, felt the warming from the sun on the hive, and thought it was OK to fly to void. Seems like every day the sun shines, I have more dead bees at the back vent hole, right now looks like a total of 100-125 or so on the snow since I first saw them. Hive does not look too bad, pulled the sticky board and saw about 100 verroa..this since early Nov., guess the FMGO is/was working. did not look at screen though, too much trouble to pull it out of the roof paper which is wrapped around the hive. Just in case, I have ordered bees/queen for spring, if nothing else, I'll put in another hive in the spring. I am having fun with this hobby, learned a lot. thanks drive careful out there.