Thanks for the thoughts all - quite helpful in thinking about what future tours might be like.
Two things in particular stand out from the comments: 1 - "Starting out with high mileage and decreasing it ending in injury is a sign of poor daily mileage strategy"; 2 - "Take time to look around and stop along the way instead of concentrating on how far you can ride."
Will definitely keep those things in mind going forward. My takeaway after the ride was that touring does not necessarily equate to endurance riding.