Assuming you have transportation already waiting for you and your luggage you can be off by 8 and get there . With traffic you are looking at about 40 min drive on a sat . We walked our luggage off to meet our driver at 8 am last week. Got right off. As soon as they announce self assist just go(be ready). If you don’t have transportation set up then I would do that at least . Our driver picked us up at port took
us to the acropolis and a few other places all while holding our luggage then dropping us off at our hotel. Hope that helps