You don't have to feed them pollen if they don't have brood, but they still try to keep themselves above the 50F storage temp so they need honey/syrup. If they

You don't have to feed them pollen if they don't have brood, but they still try to keep themselves above the 50F storage temp so they need honey/syrup. If they were outside pollinating at spring temps (in a warm area), they wouldn't need any feeding at all. It's a cost add in the warm climes so the only reason I can see to do it is for mite treatment.