10 - 15 min tops, I have driven it many times.
Take left out of BC, take right on Buena Vista Drive, another right onto to World Drive.
Stay right going through Toll plaza, take next left onto Seven Seas Drive and you're there.
10-15 minutes is what I remember. We drove from Beach Club to Grand Floridian for dinner just this past weekend. (Although, it took almost as long to park and walk inside as it did to drive there.) Have fun!