Thanks again for all your support. We finally booked a flight form 6th to 22nd of july to Las Vegas. We did not suceed in getting more free time, so we will only ride for about 10 days and now need a smaller trip around the rocky mountain region. We plan to go by rental car to Durango and start there.10 days later we will go back again to Las Vegas from there. So effectivly 10 days of riding our bikes.
Now I could again need some help in deciding on the tour more concretely. We want to do the train ride from Durango (I guess I must be lucky to reserve now anymore?) and nothing else is yet decided.
We also could need some tipps on the one-way-car rental from LV to Durango and back later - are there any "cheap" ways to get this? Or alternatives to get from LV to Durango?

Thanks again!