I think you greatly underestimate how long those units will burn.

The candles that size are typically good for 12 hours each. Figure one a night and expect to have some to spare. Three should easily get you through two nights with likelihood you leave one untouched.

The white gas mantle lanterns with a quart of fuel will burn about 12 hours on low and eight at moderately high. I really think a gallon of fuel will easily keep a single lantern going for two mights.

Hurricane lanterns with 1/2" wicks will, in my experience, run for most of a night on roughly one eight ounce filling if you keep it a bit low. For 3/4" wicks figure a pint per night. Same is true for the typical table-top hurricane lamps running kerosene or lamp oil. A half gallon per lamp will leave you a large reserve.

For a small generator I figure a gallon an hour to get you in the ballpark. A lot depends on the sophistication of the unit.