My experience is that when the power goes out I normally run the generator no more than 3 hours a day, and probably average about 2 hours. You don't need electricity during the day, or for lights at night. Primarily the generator is used to heat a tank of water and take showers. While it's doing that, it can charge batteries and run the freezer. A small inverter will run all the LED lights in the world and keep the computer online. The days of 500 watt power supplies and CRT monitors are long gone. The typical laptop pulls a max of 65 watts. A large screen LED TV uses even less. An energy star refrigerator uses about 600 watts.
People who are retrofitting houses with generators are retrofitting antique, inefficient homes. Modern technology uses much less electricity, which is one of the reasons we don't need as much generating capacity as we used to.