I have been recording temperature and RH in a top chamber for three well insulated hives, daily, along with external temperature and relative humidity. Internal relative humidity has been dropping steadily through March to a low on April 1, 2020. The unusual winter was wet, warm and humid. Now, with brood rearing and increased activities, the values are falling but internal temperatures have been really stable, 80 - 85F for days, while outside temperatures are in the 35 - 45F range.
I have not plotted the all the data collected since January when I reached an acceptable (to me) a good insulated winter configuration. Now, my first thoughts are the hives have dried out (verified by touch), water foraging is readily available, brood rearing produces more water vapor, temperatures are relatively high inside the hives, relative humidity is now in the ideal range for the brood brood rearing. Apparently simple bottom diffusion and condensation is keeping relative humidity in an ideal range with little effort by the bees except foraging for water nearby. I hear no fanning, removable bottom boards are wet - it rained recently. My conclusion is things are balanced - easily controlled by the bees. The bees have honey, rearing brood, flying in acceptable weather, pollen coming in, foraging in the dirt I turn over in the garden and I saw Dandelions yesterday - it's Spring. All is good for 8 hives, the ninth has a drone laying, 1st year queen.