I heat my home with wood as I mentioned, BUT I still have an oil furnace which my insurance company lists as my primary heat source - I pay an extra $50 a year for a 'wood stove rider' on my policy. As Highlander said, you need electricity to run any forced air heating system. Wood is the way to go.
I use a couple of these eco-fans on my woodstove to move air. They use the heat differential between the surface of the stove and the cool air above it to generate power so they work in power outages. As long as the stove is hot, the fan spins - pure magic as far as I'm concerned =)
http://www.leevalley.com/en/gifts/page.aspx?cat=4,104,53209&p=50246
I have an eco-fan too. Notice there's no pitch to the blades and they move almost no air.
If the power goes out, wood is the best answer.
You could make a temporary stovepipe outlet. Concrete backer board over an opened window with a short pipe through (obviously far enough out so you don't catch fire to anything). You won't always have it there but if you need it.....
For forced air you could run power to just the furnace. Get a good sized inverter that hooks to your car battery. 1500w at least, 2000 is better. For sure your furnace will run off a single 15 amp circuit. That's 1500w. Yes you'll have to idle the car while the furnace is on but couple of hours on, couple off is better than nothing.
Where your furnace is direct wired you just splice in a receptacle and plug. When the power goes out you just unplug from the house, plug in to extension cord from your car inverter.
Cheaper than a generator, quieter, less fuel burn.
If you are without electricity wood is the ONLY way to heat. Everything else WILL run out of fuel. I agree with the idea of having what you need to rig a wood stove or heater... some bricks for a fireproof base to put your stove on, cement board to allow you to route a chimney pipe through a window and stove wire to hang your stovepipe from on it's way to the opening. The greater length of chimney inside the dwelling the more heat stays inside. A secondary approach is to pre plan what part of the house you will live in and have the means to isolate this area. It is doubtful you will have the resources to provide heat to your complete house.
JAB
I agree that wood is the way. Last winter we had a bad wind storm that knocked the power out for 3 days. In our neighborhood, some people had generators, but basically most people evacuated, which is sad. But we did very well. Heated bath water for the kids on the wood stove and cooked most of our meals on it too - the rest on the Coleman stove.
This year we got an eco-fan for it and it works well.
Just have to get some wood stove repair preps in order still. An earthquake will take our chimney down so would like to get some stove pipe and sheet metal to make a make-shift chimney if needed.
When i built my house 20 years ago i put wood burning furnace in my basement that heats my house (hot water radiators) and also heats my hot water.My heating system works on gravity or i have option to use recirculating pump.So i am not concerned about hydro.I had to get my insurance to come to the house so I proved it to Him the safety of the system.I installed it myself so i made sure it is super safe.In summer time we heat water with home made wood burning water heater.Little extra work but no hydro and wood is free.That saved me few bucks over 20 years.
Henry