There are a lot of negative things to say about movies being split up into different parts these days, but it actually works in this case. The first act of the musical ends on a really strong note and ending the movie there results in one of the most satisfying final scenes in a movie I've seen in a long time.

Musicals have been doing this right for a while because they always want to go into intermission with a bang that gets you excited for the second act.