I'm a planner, and I don't like having to "make do" in a case when no CGs would be available. In the fall, that's a special consideration on the route you're thinking of, since many CGs that far north will have closed by October, certainly by the end of October. Anyway, given those 2 points, I would be starting to plan - especially pinning down the general route - about now, a year or so ahead, and looking to making reservations in places like national & state parks, other popular tourist areas, and on weekends, between 6 and 8 months ahead (many state parks allow that much advance time for reservations, and usually fill up pretty much right away - especially these days, with RVing so popular.) That's just how I'd handle it. (Since you asked. :) )