I did the TransAm last year. Good luck to you. It will be an incredible experience. I'll be following your journey if you want to do posts. Also, happy to answer any questions for you about specific towns or whatnot as you approach them.
I am driving to Burlington, doing the long-term parking thing and taking a shuttle to the start line. We'd love to take you and you'd be very welcome to join us...the trouble being the "us" part. I have a Thule rack that can carry four bikes, and carrying four people isn't a problem if it weren't for all the gear we'd also be carrying. I'm thinking it could be tight riding to Iowa with a bunch of camping gear on our laps. Maybe an inexpensive rooftop carrier could provide a solution, but we'd still have to figure out how to get you from Burlington to the start line. I'm sure we can figure something out though.