A 6,000 watt generator can power enough appliances for survival if the normal electricity supply is interrupted. It would handle a 120 volt load up to 50 amps, which should provide heat and light and keep food fresh.
An electrical appliance, especially if it incorporates an electric motor, will draw a spike or surge of power when initially powered up. This needs to be considered when calculating the load the generator will have to deal with. A home computer with a small monitor typically draws 400 watts in use but will spike up to 600 watts on startup. A medium sized freezer or refrigerator which typically draws 1,200 watts can spike at 2,000 watts, while a 750-watt microwave oven will surge up to 1,000 watts.
Medium-sized generators will power enough appliances for survival: refrigerator, freezer, furnace fan and lights. But avoid knocking out the generator's circuit breaker by starting appliances one at a time to keep the surge low.
Switch On and Off
Not all appliances need to be powered continuously. Motorized appliances can be run in turn: Run the freezer for an hour, then run the refrigerator and then run the well pump.