It's not set in stone but we estimate the final game should have around 50 management sessions in total. It will be enough to explore quite a bit of content, but by design not enough to go through all the possible storylines.
Do keep in mind that things right now can feel more restrictive than they will in the final game, because we really didn't give a lot of time so far... Plus we are trying to pack in as much content as possible now so it doesn't feel empty later when we get to the next part of the main story.