Agree with above post. If it were me, I'd be allowing 90 minutes just to be sure. WL is one of our favorite resorts, but transportation over to Epcot is such a project that we just take the car.
We have done this journey several times and we apparently take a totally different route then previously mention.
We catch the monorail to the TTC and then monorail to the CR and then boat from CR to WL. It typically takes up about an hour but for us it is better than waiting for a bus in the hot sun.