PA has 50% more ground troops, more tanks and more tube artillery. Roughly matched on aviation assets, except NY has more Reaper drones and airlift capacity. DOD stripped PA of fighters, and more importantly, our A-10's. Bastards. If we still had our A-10's, NY would secede us the territory without a scuffle.
Otherwise, operationally, the Governor of PA would have two tactical choices. Defensive. Forward deploy bulk of units to Scranton, send a combined arms force of armor, infantry and tube arty to secessionist zones. If NY objects, crater their major highways. There's no way NY has the ability to dig out heavy armor with infantry support, unless the USAF lent them a lot of air support.
Offensive, do a thunder run with damn near all of our armor up Route 87 to their Albany. Book time for that run is 4 and a half hours. Two and a half hours would be in enemy territory. It could be made in 3.5 hours. I'd just load the Abrams onto low-boys, with the crew in the tank.
Same is in reverse, technically for NY. Except our population would massacre NY troops before they got comfy at our Capital complex. They have 10k troops, but a civvie population that isn't nearly as well armed. A lot of their troops are outside of NYC, and I don't see them as being suicidal. PA has a huge buffer zone of wilderness that is hostile to NY. Their buffer zone would prefer to be part of PA.