I do that drive every year in August, but do it from Knoebels to Cedar Point. I spend my first half of vacation camping at Knoebels and leave Sunday morning around 9am and end up in Sandusky, check in to the campground and go to the park by 4. So if you leave by 9 am that should give you a good 6 to 7 hours in the park. I think that is plenty of time considering that even a busy August Saturday the line are 15-20 maybe 30 mins tops (not including Flying Turns).