If you think about it... the engine is in the back.... the radiator/heating coil is in the front. Long process to get the hot water from the radiator piped all the way to the front of the car, and since it is especially cold out, it is cooling off before it even hits the radiator, much less the heater coil to heat the inside of the car.
All I can say is, "Thank _____ for heated seats!"
