While I would prefer to carpool it makes me a little nervous because of the tight time schedule which only leaves about 5 hours to do the ride. That should be enough time for me, you and Kate will probably be as fast or faster, but there isn't much room for flats/mechancials/bonks which increase in likely hood with more of us. I'm prepared to cut my losses and find the the fastest way home if something goes wrong but I'd hate to ask the same of you two.
Otherwise, I can do the driving, 3 bikes and 3 people is a bit of a tight squeeze in my car but it's worked in the past.