I use a pellet cooker, so I need power. Most of the time I just plug it into my RV, which has an inverter. If the power goes out, or the voltage drops, the inverter kicks in and runs the cooker. If I don't have the RV at a contest, I always have a generator.
At most contests I go to, you don't have an outlet to yourself. You share a 15 or 20 amp outlet with another team. These outlets are GFI protected. If it's raining, a wet outlet or a power strip on the ground will trip the GFI, cutting off the power to both teams. This is far more common that a breaker popping. If it happens more than once during on turn in day, the generator comes out.