Hochdeutsch is, in my experience, relative. Swiss people call the language of Germany Hochdeutsch, regardless of region. The southern Germans I've met seem to collectively agree that they do not speak Hochdeutsch and that Hochdeutsch is what is spoken in Hannover. I don't know many people from northern Germany, but I recall an instance of someone mentioning Hamburg as being the Hochdeutsch standard in their ears.