I took the advice of the experienced tourists and padded my schedule a bit. I added one day to the trip, and walked the start date back one day, to September 5. 14 days total, ride 6, rest 1, ride 7. Arrive with one day to spare before the event, so I can let things slide one day if needed. Looking at it now I see that I was too ambitious on the second half of the trip, because I was trying to hurry.
This will be much more pleasant. Still somewhat ambitious and a tight schedule but it won't blow up so easily.
Thanks again for all the help.
-Ed