In northern Wisconsin, we have about 1 1/2 ' of snow on the ground..temps down to low teens at night. My one hive (wrapped in tar paper) with ventilation holes in the side and small screened entrance in front(entrance reducer) seems to have done OK thus far. I have a single deep brood chamber, a single deep honer super which was full at the start of winter, and a small tray with what is left of a 5lb sugar cake left on top of the hive in the fall.
After the weather warms up later this month or in April, do you simply uncover your hive, open up the entrance reducer, and let the hive start to rebuild what is left of the full honey super? I haven't opened the hive this winter, but I can hear them buzzing by placing my ear next to the tar paper. Any thoughts on when to open up the bottom of the hive for ventilation..when temperatures rise to above 40-50's during the day or should I wait for even warmer weather?