Yes but it only requires a couple hundred watts to power the blower motor and electronics of a gas furnace. They're easy to power off of a small portable generator or even a cheap inverter hooked up to your car. The same cannot be said of a heat pump or resistive heater.

They are, and I have a contingency plan for this myself, but few people have the tools and knowledge required to accomplish this.

Anyone with $200-500 can go buy a kerosene heater and some sealed kerosene which will keep one ventilated room warm for awhile in an absolute emergency.

With the common skill set people have now, half the people trying it would kill themselves. :s

True, but furnaces have a much lower power draw. They are easy to run off a generator, which are common in areas that frequently lose power.