Propane consumption question

I think it more likely that you have two twenty pound tanks- ten pounders would be most unusual on even a small trailer. That's plenty of gas for a week in a trailer that size, even if you run the furnace, stove, and water heater at reasonably conservative levels.

The real limiter is usually electric power...the fridge is one of several gas-fired things that can't operate without power for thermostat/controls. You don't say what your situation is there, but a single battery can run down in as little as three days, perhaps less if you use the furnace much.