I don't know whether this is sacrelige ... but might you consider having the screening on your usual night of Saturday, in this case the 5th???
I daresay most people have plans on the 4th ... and then not necessarily for the following two days of glorious post-4th weekend. There's no reason such a 3-day holiday cannot be a pean to freedom, liberty, independence and All-American fun!!
just a suggestion.
