We did this trip a while back, do the Peter Whitmer farm last after leaving Palmyra and take the road from there through the finger lakes down to Binghamton. The Priesthood Restoration site near Susquehanna is right near there and is just a minor detour along the route to NYC. At least for me it was unlikely that we'd ever be near that part of the country again, so it was well worth it to take the time to stop there. The church has done alot of work in that area recently and rebuilt some of the original homes.