From a local beekeeper….
Bees are supposed to stay in a “cluster” in winter, neither asleep nor dormant but in an immobile state; merely pumping their wing muscles to generate enough warmth to keep the queen in the centre of the cluster warm.
However in my apiary the temperature is sometimes secondary to the presence of sunshine. If the air temperature is above about 6oC and the sun shines on the hives, then the workers come out, either to forage on the nearby Mahonia flowers or for a toilet trip (bees can hold it in for up to 6 weeks!). It must be a short trip, for if their body temperature falls below 8oC then they die.
I’m trusting they are all OK inside the hives, as I won’t open them up till late March when the temperature is above 15oC. The problem with bees flying in winter is that they use up their stores of honey, as flying requires more food than clustering, so bees are more likely to starve in a mild winter than a freezing cold one.
I’m hoping for cold weather now, not in March and April.