Restroom trailer for a November 2026 event: how much power does the heater draw?

I'm renting a six-stall restroom trailer for a 300-person wedding in late November 2026. The ground is a grassy field, and the delivery truck has clear access. The rental company confirmed the trailer has built-in heating for cold weather, but I need to plan the generator setup. I know the trailer requires a 50-amp hookup for normal operation, but I'm not sure how much extra power the heater pulls. Does the heating system run on a separate circuit? What's the total amperage I should budget for when it's running? I want to avoid overloading the generator on a cold night.