Well ... I guess the master panel (the one with the power meter on it) in most homes don't have a master breaker to disconnect the main power company line the meter is in ... from the house circuits??
Mine does, so I just turn off this breaker and then backfeed our 4400 watt roll-around house backup generator .... using a male-plug-on-each-end 240V heavy duty cord ... plugged into a 240V receptacle I had installed in the master panel. The 240V receptacle then makes hot all 120V house circuits. The electric-start 4400 generator runs about 10 hours on a tank of gas. Our master panel for the house is a 200 amp one and is actually outside the house kindof like the power pole on farms and ranches, such that the house is getting treated like an "out-building". Of course this means that when powered by our small 4400 watt generator we have to be careful with what house appliances are turned on at all times - including the water tank pump. County codes allowed our home to be set up this way when be built, so we went this route for more flexibility.
This setup couldn't be simpler - and safe for us and the power company - since I use the master breaker to switch the house off-line from the power company feed during power outages before I connect, and start up, the generator.