As general rule, reducing indoor %RH when the outdoor dew points are <55^F is most efficient done by increasing fresh air change. Do you have any fresh air ventilation? High indoor %RH during cool weather indicates a lack of fresh air change. Resulting in a buildup of moisture from the occupants and activities. Is there a crawlspace with uncovered earth or other sources of moisture?
Anyway, operate the bath fans 24/7 until humidity falls.
All occupied homes need a fresh air change in 4-5 hours when occupied. This is an important part of indoor air quality. During cold weather, the indoor dew point must be kept low enough to avoid condensation on any indoor surface. During the summer months allong with the fresh air change, keep the indoor moisture below 50%RH for comfort and to avoid mold and dust mites.
In your climate, a whole house ventilating dehumidifier is the most practical device to do all of this. Check out the Ultra-Aire 70H as minimal piece of equipment to do this. Check my past post for more info.
Regards TB
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"