They are three ways by Disney transport to get from WL to GF. Boat to Cont and then monorail to GF is one (about 30 minutes total travel time but allow at least 45 to account for waiting times; trip from Cont to GF takes about 8 minutes by monorail but allow 15 total to account for possible waits). I am not sure what the schedule of that boat is at night any more (it used to end early but that was a few years back).
Next, you can take the boat to MK and then Monorail or boat to GF (total travel time about 30 to 35 minutes but allow 50 total to account for additional waiting time). That continues to run until about 1 to 1 1/2 hours after MK closes.
Third, you can take a bus from WL to the TTC and then monorail to GF (total travel time about 20 minutes, but allow at least 35 total to account for additional waiting times). That bus runs quite late, well after both Epcot and MK close.
