Better late than never.
This is the time of year we want to have a look at the hive entrances to see that they are not blocked up. They may get blocked with dead bees as the house bees try to evict the carcases. So have a look and see that the entrances are free.
Also when the temp gets above 8 or 9degrees the bees may come out so have a look on a good day.
If you are not sure if the bees are alive put your ear to the hive wall and have a listen for the buzz.
Please let me know if you have seen signs of life.
Hope all is well.