Sounds fun. The kids will just have fun in PJs and playing with each other in tents/forts. That and snacks alone they will have a great time. The kids will be engaged with each other they probably won't even be interested in the movie LOL. You could put on the invite what time the movie will be on. That way the, No Screens Parent, can plan around it.
I’ve also seen on Tik tok people make mini concession stations so they can get their snacks etc
Some movie theaters you can rent out for 100 or so and it’s up to 40 people
I think that would be fun. Maybe pre watch the movie and have an activity like a movie scavenger hunt for them to cross off/point out things while they watch if you want to make it more interactive