Well....

The doors open at 10 am.

You should be able to find decent parking on a Saturday morning, though you may have to walk a bit, or pay more (they always bump the prices for parking when there's an event nearby) so give yourself an extra 10 minutes for that. That puts you at 9:50.

The trip will take about 2 1/2 hours drive time (conservatively), but the timezone change is in your favor, so you only need to leave at 8:20.

But, you will have to turn around and go back at least once to grab your wallet, or your DCC controller or your checkbook, or your coffee, so give yourself another 20 minutes for that. So plan on leaving at 8:00 sharp.

Of course, you could always make sure you are there on time by driving up Friday and staying at one of the downtown hotels ;-) But then you would have less money to spend on TRAINS!!!!