Thats a long way each day, is my initial thought. My rule of thumb is also about 10mph, especially on gravel, which can suck the life out of you sometimes. 129 miles @10mph is a 13 hr. day, and that’s way more than I would do.
So, Yes, lesson learned. 45-60 might have been a reasonable day.
Begs the question, what was the point of this trip ?, where you just racking up mileage or did you want to actually stop and see anything ?. Even a pavement pace at 12 mph would have left little time to do anything but ride.