You actually have to take a monorail from Epoct to the Transportation and Ticket Center first. This takes about 10 min. Then you need to switch monorails and get on the resort monorail. This has three stops before you get to the Contemporary. So again about 10 min ride.
So depending on the wait, I would estimate a minimum of 30 minutes. Maybe longer if you have to wait for the monorail.