My first impression of your plan is you are doing an incredible amount of zig-zagging and backtracking. The vast majority of that seems to be part of your goal to drive nearly all of Route 66.

If that's what you really want to do, it's certainly not wrong, but I'll tell you, it's not something I would do. While I appreciate the history of the long since decommissioned route, and there are lots of interesting little stops and towns along the way, it's ultimately just a road. I wonder if you aren't overstating the importance of sticking to that one route.

Alternatively, if sticking to Route 66 is something you are committed to, rather than doing the zigzagging of going to Albq, then all the way up to Aspen, back down to Gallup, back up to the Grand Canyon, over to Barstow, the back up to Reno via Nevada, etc - I think you'd be much better off doing a loop trip. Follow the path of Route 66 from Chicago to LA (with some small detours like to the Grand Canyon), then go up to SF, across to Yosemite, and then head back across Nevada, Utah, and Colorado. You could either go all the way back to Chicago, which likely would reduce your airfare and car rental costs, or finish and fly home from Denver.