Right. Your answers are in your links. Or I've dismissed them earlier in the thread and I am tired of a back and forth badminton here.
Now, sustainability of a British presence in Canada is dependent on their positions in Nova Scotia and New Brunswick. Reaching them is a harder task then reaching the St. Lawrence with entrenched local resistance likely to be several factors higher then along the St. Lawrence.
A British counter attack would likely spring from here and travel down the river, and once again Quebec City would be the lynch pin in re taking the area. The fate of the Native Americans would probably be much grimer, with no safe zones established by a British presence. Though, I wonder if the Americans would attempt to directly take the Hudson Bay area. Probably not due to its isolation.
The French Habitants are also a not often talked about factor. They were rather lukewarm to everyone at this point. Rather then the often enough scenarios including Canadian incorporation into the United States it seems likely that Canada would form two separate 'republics', essentially protectorates of the United States. Lower Canada would be most subject to further American settlement and would form a third layer of immigration.