Sorry to hear that, but hives need checking on, and feeding accordingly pre 'close up' for the Winter or these things will happen.
You also need to treat them for mites.
This is a bit of what I do:
If stores are low feed a sugar syrup before the hive goes into the Winter so they have plenty of readily available stores (if you don't feed or check they have enough stores to see them through the Winter you take the risk of losing your hive. And this time you did).
Stake the hives regardless. And put a large heavy block on top.
If really cold weather due I double insulate mine using WBC outers.
I keep mouse extractors on year round. Keeps the mice out but we have a lot of Hornets in this area so it helps to keep them out as too large to fit through the holes.
Don't forget to restrict doorways to help them guard against wasps.
NB: I forgot to say, I also always keep them strapped up with ratchet straps.
----------
Hope this helps a bit.