This post is a disclaimer against people trying to figure out regional breakdowns of polls.
Always figure out how they decided what riding is in what region!
Some polling firms have a set of ridings they determine to be in this or that region of the province. Most, however, use area codes. It's simple; especially if you are calling people on the phone. Area code X means region X, and area code Y means region Y
The problem is that Ontario's area code map does not perfectly align with our interpretations of what Ontario's regions are.
In fact there are a number of ridings split in two by area codes. Wellington-Halton Hills is another, where half the voters live in the 905 and the other half do not. In York-Simcoe a similar problem, and again in Northumberland.
This is simply meant as a caution to those reading the regional results and trying to produce their own projections. A high "905" number may not mean a good showing in Barrie; but a high "Northern Ontario" might.