I 'll be walking with my mom and daughter. We had so much fun last year. But we need to get up earlier as last year traffic to park was unbelievable. It's going to be tough as my kids are marching in a local city parade the day before and my oldest has a high school band field show competition the night before. Don't think we'll last too long in the park after the walk.
Walking you will be fine. The traffic is on the street, getting into the structure and parking. Plus, they don't have the trams running from the structure, so it takes extra time to walk to the gate. Last year I had been warned to leave home at 5:30, but didn't leave until about 6:15. This year I will try to leave at 5:30!
I think you will be fine arriving at 6 am, but not sure exactly when the bad traffic started. I am about a 15 minute drive away and didn't leave home until 6:15. People I know who left at 5:30 had no trouble and were right at the front at the start. We checked in ahead of time, so I don't know how the check-in lines are, but hopefully you won't have bad traffic issues.