Let's say that James Murray falls down the stairs sometime before 1774, hits his head, and dies. The Quebec Act is never passed, which angers the old french catholic settlers in the region while they are also forced to make space for british colonists. Come 1776, the thriteen colonies rebel, but this time Quebec joins them, managing to achieve independence.
The question is: what now for Quebec?
-Will they see themselves stripped of the Ohio territory?
-What will the new canadian government be like? Will it be an unitary republic like the one possibly coming soon in France? Will it be a federation of states like their southern cousin? Or will it be a Kingdom headed by either the Bourbons or some obscure royal family?
-How will they expand west, if they ever do? How necessary will foreign settlers be?