I've got a genny that can run most of the house unless all the fridges kick on simultaneously wired into my breaker panel. Has gotten me through several long term outages and somewhat frequent shorter outages (around 12 hours or less because our power company up here never trims the trees) IIRC the longest was 6 days and that was the gas stations being down as well for up to a half hour out. My shed is probably a fire hazard, but thats why I keep 6 cans filled, capped, and ready to go at all times.