I was merely using those two cities as examples. The original 6 teams (Chicago, Detroit, Boston, New York, Montreal and Toronto) and then a select other group of cities have always had great turnout no matter what.
Basically, any place north of the Mason-Dixon line and near water has a good hockey base. Dallas surprisingly, is an exception. I know a couple people who live there and they say that Stars games always sell well and they have a great presence there.