Restroom trailer for a October 2026 wedding: how much power does it draw?

We're planning our wedding for October 2026 on my parents' property in Charleston. We'll have about 140 guests, a tent, dinner, and an open bar. The venue has limited electrical outlets, so I'm looking at a restroom trailer instead of standard portable toilets. I want to know how much power a restroom trailer draws so we can plan for a generator or hookup. The ground is level grass, and a truck can reach the spot easily. How many amps or watts does a typical restroom trailer use? Does it vary by size or features?