[Crowbob]

10KW is plenty. In an emergency situation, you will conserve and limit power usage anyway. A/C becomes a luxury. Furnace, well (if you have one), hot water, refrigeration and a few lights are all you need. Even then, you can rotate usage such that no two big power consumers are operating simultaneously.

I have a 12KW (peak) pto gen (off a diesel tractor) and a 2KW Honda (gasoline) gen. Between the two, I'm good for a couple weeks off grid.