FWIW, I work in the utility industry and with those amounts, here's a few ideas:
- Get the furnace checked. The September number for winter heating already seemed higher than it should. Is a thermostat in a bad place or ducts not fully open and circulating properly? Generally, closing vents in rooms backfires on heating bills as cold air is sucked into the static air intakes and costs more to cool as it hits the furnace. If the HVAC was done right, let it breathe!
- air leaks! Look everywhere in the attic area especially and door sills. I buy cheap softer type of rope at Lowe's and use as weather stripping in the window jams in the winter. Cuts drafts and costs a fraction of weather stripping they sell for $5-$10 a window. A whole coil of rope is only $15 or so and does the window sashes on the whole house.
- How are the ovens used int he kitchen? Can you use a small toaster oven more? After air conditioning, ovens, clothes dryers and fridges are energy pigs.
- Is the dishwasher "heat dry" cycle used? That sucks down kilowatts if used every time.
- Is the water heater electric? When was the last time it was checked to make sure all the heater elements are working? Generally there are 2 elements and one may be dead, causing the other one to work overtime. A simple voltmeter on the unit will tell usually.
- Check the fridge. Check airflow and vacuum the heat coils underneath and clear any obstacles in front of vent holes on the front or back of the unit. Can you improve airflow underneath by pulling out from the wall a couple of inches?
- Ask family for LED bulbs for Christmas/holiday presents instead of other junk. Receive the gift of savings!
- If the house is electric for heat, water heater and/or stove/oven, check with your utility to receive an "all electric" discount. Ours give those discounts if you don't use natural gas (or only 1 thing is gas maybe).
Hope at least one of these makes a difference for ya!