It's feasible, but I'm not sure how often the Contemporary to Wilderness Lodge boat runs and if it runs as late as the Magic Kingdom is open. I've only taken the boat back and forth between the hotels during the day.
I'm glad they now have a bus in addition to the boat. The boat to WL at MK closing time was always a congested mess IMHO. We used to take the monorail to the TTC and then take the bus to the WL.