Hi,
Many folks can heat 100% electrically. Replace the return air grill on the furnace with a fan. On my rv that circulates warm "living space" air under the cabinets and pushes some air along the furnace duct work. I chose to use a dual window fan unit which is controlled by a mechanical thermostat that lives beside the water pump next to the outside wall of the RV.
The fan unit draws just 23 watts and works better than a 1500 watt fan based heater which I tried using inside the cabinet.
Here is a link to a
cost comparison calculatorAt the moment, propane is "sky high" because of recent shortages.