Don't kid yourself. The studio and the cinemas will drag it out as long as possible.
In my local cinema, Ant-Man finished two weeks ago and F4 still has virtually the same number of screenings per day.
They are making the film an option to casual visitors who just go there wanting to see something. People don't care how many of them are in the screening, many people prefer it as quiet as possible so they can have a great choice of seats and so as there is less disturbance and noise from phones, munching, chomping, slurping, giggling, coughing, talking and the usual idiotic behaviour of The Average Moviegoer.
I went to see Mission Impossible for the first time last night. Great movie, but there were only three of us in the auditorium at a peaktime Saturday night screening.