I'm trying to make 500 gallons of heating oil last all winter. Use a kerosene heater to heat main living areas and drastically turn down the heat to the remainder of house. Besides, everyone should have a kerosene heater for when the power goes out. Replace or install better weather-strips around door jambs. Install sweep at bottom of entry doors.
Caulk gaps too.
Install dryer duct diverter to keep dryer exhaust indoors . This has potential problems, such as excess humidity buildup in a small room. Air circulation must be maintained with fans. Add insulation to the attic. Replace old drafty windows.