I am thinking that two 2X3 foot 1/4in or even 1/8in luan plywood would be workable. You could lay them down one behind the other crosswise on the roof. Work from one and then step back onto the 2nd one and move the first one behind you. That way you could work your way from the front of the roof to the back and probably be able to do ok. Make sure you have a nice long handle on both the squeegee and the roller. This would allow you to reach both sides easily from the plywood surface centered in the middle of the roof.
Might be kind of slow, but I think it would work and is the way I would go. You would have the sides already done via brush and the ladder so all you would worry about is the flat horizontal surfaces,
By the way, I did mine in the campground also during our winter stay in Tampa. :)
Barney
