I think an ideal situation would be to figure out a way to connect up the Empire Corridor with the 3C Corridor by either extending a few Empire Corridor trains to Cleveland or extending a few 3C Corridor trains to Buffalo Depew or some combo thereof. This of course will require extra equipment over and above what will be necessary to run the basic Corridor services, so might take a while.
What calling times did you have in mind?
The Lake Shore Limited takes roughly 12 hours to get between New York City and Cleveland. It seems to me that the only way to have a train serve the 3Cs and NYP at reasonable calling times by extending an existing Empire Service run is going to extend a train that currently terminates at ALB to continue all the way to Cincinnati via Buffalo and Cleveland, and will require sleeping cars, a diner, etc. (241/257 departing NYP at 7:10/7:20 PM seem likely candidates; the departure slot before that at 5:20/5:45 might also work, except that the Ethan Allen Express uses it on Friday; and the eastbound train might arrive at NYP 7:35/8:35/8:45 AM as 230/250/232; this all assumes that things haven't changed since the two year old timetable I'm looking at.)
It's probably also possible to have a Cincinnati to Syracuse or maybe even Cincinnati to ALB day train.
Will CSX welcome an additional ALB-Cleveland round trip?