What's 700 Watts anyway...
As my Alaskan friends can attest to, truly cold weather (NEVER occurs south of the Mason-Dixon, and very rarely below the 45th parallel) requires far more electrical gadgets. My winterizing included two battery heating pads (~250 watts/ea) and two silicone pads on either side of the oil sump (~200 watts/ea). My '99 with an Auto also had another pad on the transmission pan, for an additional 300 watts. When it's REALLY cold, plugging in takes a bit longer than 2 hours to work. There's been times I had to cycle the grid heater twice to get the truck to fire up, and this was with the vehicle plugged in overnight. What I guess I'm trying to say is... you paid 30K, 40K, or more for something that could last 15 years after it's paid off. Why quibble over an additional $20/month. I just look at any costs above that as the price I have to pay to drive the best truck on the planet in the best location on the planet and, IMO, it's really more than worth it!
-Adam
(Results not typical; your results may vary based upon dependency status, parental/child concerns, desire to subsist in an environment where you are NOT the top of the food chain, and the ability to deal with Mother Nature, who visits whenever she gets a chance, but usually at the most unusually inconvenient times :-laf )