Consider what you already have:
Your barbacue: Is it connected to the city gas line? Can you reliably light it in a strong wind? Do you have a backup propane barbacue such as a portable unit? Do you have a heater attachment for the propane tank? Do you have a backup charcoal barbie? We have all. Kinda a sliding scale for cooking methods. Last method is the firepit!
Do you have a Dutch oven? Then you have an oven that works on your barbacue. It takes a bit of practice to make bread or rolls but works well.
I changed from electric stove to natural gas at Level I. I changed the water heater from oil to natural gas as well. Generator/ tranfer switch followed at Level II. These are easy changes if you have natural gas service in your area. When you have a blackout, you can still cook.
As far as heat, my plans call for a wood stove piped out the window, sitting on bricks, encompassed in a tile wall on cement board with exhaust out a window, safely insulated. Its the doomsday heater and uses wood, but sits in the shed for now.
Get the right exhaust pipe if you try this. http://hearth.com/emergency.html
Perfect setup outside. Extinguisher sits next to it. Safety first.
Window mock up starts at around 11 minutes.