We have been on two lengthy tours. Once on separate machines,and last year riding two(or I should say 3, including our pooch Kiddo)up,dragging a small tent camper. Last year we maxed out at a bit over 400 miles in a day. That was more than enough for us, and we are in the same age group as you. We usually go around 100 miles, then stop, gas up, let Kiddo run around for abit, eat a snack, and head out again. So usually our stops are around a half hour. So: 400 miles= around 7-8 hours plus 1.5 hours for gas ups,etc. It takes (us) around 10 hours max for us to travel 400 miles.
This trip to Durango, we have 3 scheduled overnight stops in 1300 miles. Way less than 400 a day.
We
refuse to be hurried..takes the fun out real quick. nojoke

Brad