Cross the Erie Canal off of your list. I rode it from Buffalo to Rochester and it is anything but "epic". In fact it is down right boring. The only plus sides for me would be the quaint little towns and the inlet crossing on a private motor boat at Irondequoit Bay. But then we were off of the trail by then.
It really does not get much better after Rochester from my understanding in fact it gets worse as you have less and less trail and more road.
If you do it consider an organized ride. Then you would get a history on the area and that might be interesting.
Consider often overlooked northern Italy. The lake region is awesome.
This photo was taken on a trail system in North East Italy / Southern Austria. My suggestion would be to fly into Venice, train to some place like Verona or Trento then ride the Brenner to Innsbruck. My mistake was to train to the top of the pass. I imagine I missed a lot because the ride down the other side was wonderful.
If you have the cajones you can ride the Stilveo Pass which is in the same area as the photo above.
Stateside consider the Slekirk loop north of Spokane. Plenty of amenities along the way but you still have the sense you are away from it all. If there was any less traffic on the road it would be a bike path. About the only thing unnerving is the occasional logging truck.
And the loop has the Galena Trail. Short but very cool trail.
The loop can be done in 9 days depending on your route. I did not notice camping as I was not looking for it but I am sure it can be had. There are a couple of warmshower and BF members along the way.