As someone said earlier, my 3 hour guesstimate is for 2-6 inches or so. Over that it's going to go up.
Am I going to have to do it next?
I'd push that section on the far right (the square) first,
Then I would push the long section (top part), it looks like it all goes to the islands by the entry way, longer runs are most efficient.
Then that underground parking entrance (I finally figured out what that was), push that out of the way
then that little smaller square section (bottom left)