With my starved bees, they were many dead on the bottom board, and many still in a cluster, most with heads stuck deep into the empty cells. There was a whole super of honey above them, but they had eaten the honey directly above them, and it was apparently too cold for them to cross that bare area to get to the honey above. My lessons learned: a) Leave more stores, and b) Stop messing with their stores earlier, and let the bees move it to where THEY want it. Putting a full super of honey on top in the late fall was not the great idea I thought it would be. I should have put it on in August or Sept.
It is heart-breaking, but do not blame yourself unduly. Learn what you can, but accept that there are some things over which you have no control. If they starved, maybe you will leave more stores next year. If they have ice/excessive moisture inside, you will want to address the ventilation. If they were just weak, then it's just nature's way of keeping the overall population strong.
Bees die in the wild, too. It's just tougher when we make ourselves responsible for them. Hang in there. The hurt subsides eventually.