The 1837 rebellion in Upper Canada was a broadly pro-American spark, while in Lower Canada it was a substantially larger potential war of independence that got nipped in the bud. The first Métis rebellion was less an attempt to break away from the British sphere and more an effort to get a better position versus the Canadian government, while the second was a despairing last attempt at something. The Fenians were not credible, not outside of something larger like an Anglo-American war.
The current Canadian state is a product of deadlock in the mid-19th century Province of Canada, a single state combining what is now Ontario (once Upper Canada, then Canada West) and Québec (once Lower Canada, then Canada East) in a single territorial jurisdiction with a single parliament. Ethnic and economic differences between the two parts of Canada quickly lead to deadlock by the 1860s, this deadlock becoming so serious that Canadian politicians seized on half-hearted Maritime discussions of political union as a way out. The modern Canadian union created in 1867, a union of provinces, would be a large polity more capable of promoting economic development across British North America that would also allow the two parties to separate. If the Province of Canada somehow works better (unlikely) or if the two provinces are never merged in the first place, Confederation could be postponed.