I crunched the numbers, and this year's Dec/Jan/Feb usage is 22% higher than the average of the previous three years (2000, 2001, & 2002) for those same months.
Does that sound reasonable given the programmable thermostat's added efficiency?
You stated 20%, was that a guess, or is it documented that this winter is resulting in 20% higher fuel bills on average? I haven't been able to find anything in that regard.