Colonies for sure do not regulate humidity in unoccupied areas, especially away from brood, during the active foraging season.  I would assume the same holds for areas away from the winter cluster.  So whatever happens in those areas is a passive result of air temperature and amount of water in those regions, both probably indirectly influenced by the cluster heat and humidity releases, but also by hive insulation, outside temperatures and humidity and the killer by cold: convection.

Screened bottom boards may be useful for areas with high humidity and not too intense winters, but I would think they really tax colonies in really cold winters, again during high convection periods, i.e. killer winds.  In an overwintering experiment with Russian bees in northeast Iowa in the early 2000s, colonies with screened bottom boards lost more weight than colonies with regular bottom boards.  Statistically significant difference.

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