If the monorail isn't running when you leave EPCOT (there are some time frames where the monorail hours are limited due to work being done), there will be buses running in its' place.
thanks! But what I was really hoping is that we can take the monorail from the poly TO epcot at about 11:00pm when EMHs are until 11:30. We are staying at BWV and were just going to walk through Epcot out the back entrance to the hotel