Presumably, this is 'french Canada' ruled by Britain.
Timeframe? Right after French and Indian War is going to be most likely. Lower 13 aren't completely pissed at mother country, and the French don't want to be part of the British Empire.
They don't have the population to rebel straight up, so it has to be a guerrilla affair. Britain is pretty worn out at this point, so they might be war weary enough to give in. Lower 13 aren't going to be gung ho to travel north just to quell a rebellion (Frenchmen remain, but France is gone, and an independent Canada poses no threat), antd won't be happy to pay for it, so don't count on them too much.
Ultimately, Britain has the capability to quash it, but a determined effort by the French Canadians would make it interesting.
Effects on the lower 13? It gives Britain something to do with leftover officers/troops, so it removes that irritant from the colonies. It shows the lower 13 that resistance is futile. Northern states, New York especially, will benefit from selling supplies, so they'll be happy for a while. But, the lower 13 will be put out by the effort (taxes, manpower) and that'll be a major irritant. It would certainly change the dynamics of the situation that led to revolution.