This is the schedule for the monorails right now regardless of park closing time.
Resort Monorail – 8:30 AM to midnight
Epcot Monorail – 9:30 AM to 11:30 PM
Express Monorail (MK monorail) – 9:00 AM to 11:00 PM
So if staying later than that, like 2 am..only options are bus or ferry boat