Do the Americans have New Orleans in your proposal?
Nope, their frontier stops before the Mississippi, so that's why I wonder where they may turn to if going West is not feasible...
The Deep South Plantation culture really wants to expand into Texas, but Georgia doesn't need to be a slave state for the American Revolution to happen. That expansion could be entirely yeoman and sharecroppers. Settlements in the Apalachicola, Mobile, Pascagoula, and Pearl River Drainage Basins don't need the control of New Orleans, but they do need West Florida.
Getting access to the Tennessee and Ohio River Valleys were fundamental components for the American Revolution. If the Americans can get over the Appalachian Mountains then they will push to the Mississippi River. If the Americans get access to the Mississippi River then they would be willing to fight a war to dominate New Orleans and the immediate flood plain of the Mississippi River. If Americans have control of the Lower Mississippi River then there is no geographical feature obstructing access to the Rocky Mountains.
The most likely differences are that the Iroquois become even more powerful in the Fingers Lake Region in the 1790s than they were in the 1770s, and the Americans are incapable of defeating the Western Confederacy. Those situations probably mean that the British are even stronger in that part of North America than OTL. But the Western Confederacy isn't going to be able to project power into West Virginia, southern Kentucky, nor Tennessee indefinitely. The Americans (the Scotch-Irish in particular) won't just stay in the Tennessee River Valley either, they will spread out. To prevent Americans going through those areas, you need American self regulation. That "regulation" in Appalachia is going to be a real sore spot, lots of rebelliousness over that.
This sounds like the United Kingdom negotiated a treaty of secession with the Continental Congress. In such a situation, the New England Yankees aren't going to want to invade into Quebec or Nova Scotia. If relations with the Western Confederacy or the Iroquois become too antagonistic for the Americans then there will be war mongering in New York, Pennsylvania, and Virginia. The Yankee state governments may say to their people going over to settle in the NW frontier "oh well, you knew better, we had a treaty, tough luck."
Americans will move into Canada, first the Loyalist, but then the separatists and at greater levels than OTL. That does have the potential for civil strife and war. Eventually the British/Canadian/American settler wave will move into Cascadia. Maybe an earlier, looser, Commonwealth.