Another way to think about planning the trip: 8 weeks is a lot of time to put together for a trip and not a span of time you will often have - at least not for me, even in retirement - so I would skip locations that are close enough to cover on more normal trips of shorter duration.
For me (also an east-coaster), that generally means driving like blazes for 3-4 days (stopping only when sleep is needed at rest stops, flying J, Walmart, etc.). That way I start sightseeing at places I can't practically reach in a 1 or 2 week trip.
So my initial target (where real camping and sightseeing start) is likely to be Montana (Tetons, Yellowstone, Glacier) and then points west from there. With eight weeks you even have a shot at Alaska.
Have a great trip.