Holy 🞵🞵🞵🞵 this is really bizarre.
OK, First of all, no one refers to this region as "NOON". It's Northern Ontario. If you need to abbreviate it, we use "The North" but you can say "NO". We won't get mad at that.
The principal regions of Northern Ontario are not "Northern, Central and Southern". They're Northwestern, Northeastern and the Far North.
Largest cities: Sudbury (160k), Thunder Bay (130k), Sault Ste Marie (80k), North Bay (65k) and Timmins (43k).
Our population corridor isn't "Thunder Bay-Timmins". While at the same latitude, there is virtually no population centres along that axis and it ignores the other three cities in the region. The real "corridor" is from Kenora to North Bay, along Highway 17, and it does follow a roughly straight line, and Timmins is an outlier (it's on Highway 101, which bridges Highways 11 and 17 in the North East).
And while the "Arctic" (they're subarctic) regions are isolated, they certainly factor into the region's population. Over 40,000 people live up there, that's a sizeable percentage of our populations. You could create another Timmins if you put them all together in one place.
Trivia: when you consider that Thunder Bay and Sudbury are both made up of multiple cities amalgamated in the second half of the previous century, and if you consider Port Arthur to be separate from Fort William, and Sudbury and New Sudbury and all the other villages to be separate communities themselves, then the largest population centre in Northern Ontario is Sault Ste. Marie. It's also the oldest and most central, so it makes a logical choice for capital if we ever do split up.
Thunder Bay has the best building to convert into a legislature, though.