given that my hypothetical riding looks like windsor or london or waterloo, it's entirely possible for the conservatives to be up by 5-10% in "southwestern ontario" and not actually win any seats - because they already have all the rural seats, and they'd need to be up by 15-20% to actually swing any urban seats.
these are rough numbers, but the point i'm making is accurate.
so, these regional polling categories have the potential to be deeply misleading.