If we are doing the power lines on Saturday, which I think is the plan, you could leave any time you want, as the access road intersects the power lines a few times. Depending on which one (Craig or Quin) is on Sunday, then they are more of a trail that needs to be completed or turn around. What you drive and your experience may also limit which one you want to do. I'll let logan set the minimum tire size etc for day 2, but I wouldn't try either with a stock vehicle. You could always come to both if you wanted.
--EDIT - to clarify, by "I wouldn't try either in a stock vehicle" I mean either Craig or Quin, not the Saturday run.