I do realize that for most people 3-4 hours of a single movie would be rather pushing it, not to mention the strain on the projectionists at those movie theatres who are still using actual Film and are not digital yet. I remember my days doing that and the longest movie I ever came across was Master and Commander, which almost filled the Platter up. It would also be somewhat of an oddity to have an intermission in a movie, not only because nobody is used to that, but it also slightly breaks the temporary Suspension of Disbelief that engrosses the audience into the story.
I would have no problem with that, as I can keep my disbelief suspended and re-enter the story with no problems even if the intermission lasted 10 minutes, which is roughly the amount of time needed to change from on platter of film to another and re-thread the projector.