Not into doubling back.I can relate to that. I avoid doubling back like the plague once underway, but the logistics of getting to a tour are a different matter IMO.
BTW, one thing you might consider is whether you really want to start in the East. If you will be using air travel between the west coast and home, I find it is easier to get the flying out of the way up front. It is easy to buy a ticket for a specific date when you know the exact date for sure. It is much harder to know when you will finish than to know when you will start a trip. Amtrak is much easier to deal with for changing a departure time/date.
We found the Appalachians to be the hardest part of the trip and were happy to save them for the end when we were well road hardened.
With regard to weather, what date you want to start will also play into direction of travel. An early start favors starting in the east. June or later favors starting in the west.