A fellow pedant

. The thing is, as I see it, if you aren't going to be accurate, why bother?
Pre-Confederation Canada is a geographical mishmash that can be hard to untangle. What is now southern Ontario was part of the French colony of "Canada" from 1534 to 1763. These days that colony is also referred to as New France, although at the time that was a more general gepgraphical description that covered anything vaguely French in North America, including Acadia and Louisiana.
After the (Seven Years' ?) War in 1763, the colony of Canada was ceded to Great Britain and became the British province of Quebec. That province included the southern parts of what is now Ontario and Quebec, as well as the US midwest (the area south of the Great Lakes, east of the Mississippi and north of the Ohio river). The parts of the Province of Quebec that are now in the USA were ceded to that country by Great Britain in 1783 (Treaty of Paris).
What was left of the Province of Quebec was divided into the separate colonies of Upper and Lower Canada in 1791; UC being the southern part of modern Ontario and LC being the southern part of modern Quebec.
The two colonies were reunited as the Province of Canada in 1841. What had been Upper Canada was now an administrative division of the new united province, called Canada West, with Lower Canada becoming, of course, Canada East.
1867 saw the various British provinces in North America, except for Newfoundland, join together in a confederation. To confuse everybody they called the new dominion Canada. What had been the united Province of Canada since 1841 was divided AGAIN, with the eastern part joining the Dominion of Canada as the Province of Quebec and the western part becoming the new Province of Ontario. Both of these provinces were much smaller than they are now. They both gradually extended northwards and west-/eastwards over the coming decades.
The northern part of modern Ontario was originally part of Rupert's Land, which was administered by the British Hudson's Bay Company. Control then passed to the British Crown and Rupert's Land became part of the Northwest Territories. The area was then reorganised several times over the decades, with northern Ontario sometimes being part of NWT and sometimes part of the District of Keewatin. Control of some areas of western Ontario was disputed with the Province of Manitoba for a while.
All fascinating stuff, but it does mean you need a good idea of where a Canadian town is, and when an ancestor lived there, if you want to be "chrono-geographically" accurate.