Larry, I don't really see any holes in your plan. I think that people biking short trips can have a scheduled route but long time travellers usually endup following the weather. Usually we (long time travelers) start out with a more or less scheduled route but most of us endup changing it because we quickly become behind schedule. So when travellers don't have a strict timeline, what they endup to do is going where the weather is good. Basically you're taking a short cut in your plan and I think it is a smart way to do it. Scheduled and planned route are only good to stress you. No plan = Goog Plan, right Stephane? Of course it is not always easy to follow the weather as seasons can change faster than we can move and often the weather turn up to be different from expected. You may have much colder or warmer night than expected. it can rain much more than expected so it feels colder, a high humidity or very dry condition can give a different feeling to temperatures etc. But the idea is good as long as you know that there is no 100%-perfect-weather journey. And on a last note, persoannaly I would not rent a car just because the weather is getting rough. Whenever I had extreme conditions during my journeys is also where I have my best travel memories. I am not sure why but it is the way it works. In any case, you'll have a blast!