Depends. Have you got a General Admission ticket or are you in a grandstand? If it's General Admission, decide where you want to watch from and arrive at the track very early; 6am is pushing it a bit! A lot of the places with the best views fill up extremely early.
This was straight from Club to Abbey at about 6am when I went in 2005, still plenty of space but if you look down at the banking at Club, it's already packed:
That year we ended up with a decent view at Bridge (no longer available, obviously):
But if we'd arrived 20 minutes later, I doubt we would've been able to get close. Anyway, if you've got a grandstand seat, don't worry about it. Traffic's far better than it used to be. Takes much longer to drive out of the circuit after the race than it does to get in.
Sorry, this post is probably too late!