By then, if English forces had already gotten to the plains, France was in trouble.
Assuming we go somewhat earlier, France's control of the Ohio and Illinois countries were assured. Probably even up to the Appalachian Mountains' edge.
Perhaps the Hudson Bay valley and Acadia returned? Some Cajuns returning back there? Newfoundland taken if Placentia is lost? Increased settlement of all the areas mentioned above since New France has been given a longer lifespan?
The American front was a total sideshow to the 7 years war.
Even if France scored a total victory in America their European defeats would overule these a lot.
I think you need to define what you mean by win. They could win that battle which would delay the conquest of French Canada. [OTL it wasn't until the following year that Montreal was captured]. However the British would still have a fleet blockading the St Lawrence and by that time had won control of the seas so almost certainly they would be back for Quebec the following year. French Canada is a weak and thinly populated settlement totally isolated from outside assistance. Even if for some reason it wasn't actually conquered during the fighting it might be traded away by France at the peace to regain the sugar islands lost in the Caribbean.
In terms of what some TLs that refer to a French victory mean, i.e. then conquering some or all of the British colonies, that would be ASB, especially with a POD of late 1759. They simply don't have the resources to conquer and occupy such a large and populated area.