If you want 60-70 going south, then you need to consider the return trip on PCH through Laguna Beach and Corona Del Mar. Getting up early is ok to avoid going but coming back is a bit of a problem.
I am from Huntington Beach and the Marathon organizers already pitched up the tents on the parking lot. That Marathon is on the same day as Super Bowl Sunday. There will be like 21,000 runners there. So don't go on Super Bowl Sunday, this Sunday.
You want to avoid H.B. altogether this Sunday.