Not sure if you're already on the road, but I thought that if you took the time to read the book Blue Highways by William Least Heat Moon you might get a good idea of travel routes and time. He took only the scenic, blue highways and lived in his van during the trip. I thought it was extremely realistic in how long it would take to drive over more rugged or mountainous terrain -- or in snow or rain. Anyway, I read this book while on the road last year and I felt Least Heat Moon was sharing my same joys and frustrations. By the way, if you take this trip, I'd be interested in you posting your experience--'just how long did it take and where all did you go?! Enjoy.