well, I follow a 'live and let die' methodology. otherwise known as natural selection.
What type of foraging is immediately available for pollen sources around you? If there are early pollen sources within the immediate area, that may well suffice.
Bees will spend any time it is warm enough to fly doing that. They will forage and bring back what they can, while they can. It is mid november in Nebraska now. every time that tep gets to 55 ish, I see some few bees flying while the warmth holds out. Then back to the colony before it gets too cold in the evening again.
I say this because even though bees do cluster in the winter, that doesn't mean they are unable to provide for themselves. They are simply using their resources as a whole to maintain a survivable temperature. If any bees can forage, they will. They will do it in the Spring as well.
I am very selective about where I place bees and have turned down offers for space because I did not feel they offered enough immediate foraging resources for just such situations. but, I can be picky as I am not a commercial beekeeper and have to tend that number of bees.
think about planting some early spring and late fall/early winter pollen/nectar producers in the immediate areas of your hives. that can be a big help to them when they are taking advantage of warm breaks and taking short flights.
because when it warms up in the hive, they are consuming stores and will need to replenish when and however they can.
but, that's just my own two cent. your mileage may vary.
Big Bear