Can a restroom trailer be leveled on a slight slope for a fall wedding?

Yes, a restroom trailer can sit on a grade like that, as long as the crew levels it with blocks under the stabilizer jacks instead of just dropping it on the grass. We had a six-stall on a sloped back lawn for a fall reception and learned a few things the hard way.

They level side to side first, then front to back with the tongue jack. On our slope the downhill end ended up sitting high on a stack of blocks, so the steps didn't meet the ground cleanly and they had to add a landing. Check the step height on the door side before guests show up, because that bottom step is where people trip in heels after dark.

You notice fast when it's off. Doors drift open or swing shut on their own, sinks drain slow or pool, and the holding tank sits tilted so flushing gets weird. If the truck can manage it, park it with the long side running across the slope so there's less height to make up.

Wet October grass is the other worry. A loaded truck backing down a hill on soft turf can rut the lawn or slide, so walk the spot with the driver or send photos ahead.

Since your quote already says level ground, call and tell them about the slope now. They'd much rather bring extra cribbing than show up surprised on the day. The restroom trailer page covers the rest of the setup basics.