Sparky,
I've done RtR twice. Loved it both times. It is an incredible ride. Super well-organized.
I am from Iowa. We have no altitude! (Attitude, yes, altitude, no.) I live by the Mississippi ride, tho', so have lots of hills. That's what I rode. I rode the hills. Every hill I could find. And then I rode them some more. I learned to love the hills and climbing. RtR was challenging, yes, but not to the point that I couldn't enjoy the ride, the people, and the beautiful vistas. Not to the point of exhaustion.
I rode past many people on the climbs. I noticed the altitude, but it didn't make it impossible, just a bit slower. Hydrate well. That is important. Enjoy all the beauty around you. Talk to people riding. Do not stress out. You will be fine. Train as much as you can and then just go and ride.
annie
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived." Captain Jean Luc Picard