We're arriving mid-afternoon (driving) on a Saturday in June. I'd like to at least get into the MK and see the castle or a few things before our 6:30 reservation at Ohana. (It's our first trip - just won't feel like we're there until we see the castle.) I assume we just exit the park and catch the monorail to the Poly. How long should we allow to get there in time for our ADR??