An afternoon arrival for us on the 27th meant very crowded parking and very large crowds. If you do not have Quick Queue passes already, I would strongly consider purchasing them if rides are an interest to you.
You didn't mention where you were staying, but I can tell you that we drove to breakfast at the Poly from SW yesterday, and a 15 minute drive distance-wise took 45 minutes to accomplish in the traffic. And that was at 8:45 in the morning.
Last night, our "8 minute" drive from Downtown Disney took 35 minutes at 8:30 pm. Give yourself tons of time as the roads are packed and many drivers are less than considerate.