I would allow about 40 minutes to get a bus from the WL (in case you just miss one). Then it will probably take about 10-15 minutes to walk from the entrance to the restaurant.
One of the best restaurants in WDW, enjoy!!!!!!! Great items on their menu are the chowder style mussels, mushroom or the BBQ maple filet migon, and the creme brulee sampler. The pretzel bread is wonderful also.
We went from WL to Le Cellier, and it took 45 minutes to an hour. They want you to check in 10 minutes before your time. We left 1 hour before our ADR. I would leave your room at 6:40 and plan on walking quickly through Epcot. If you don't already know where Canada is, I would look at a map of Epcot so you are walking the shortest way possible.