I don't think this changes the point. A single McDonald's franchise would pay its employees a different minimum wage than McDonald's Corporate, and Fred's burge

I don't think this changes the point. A single McDonald's franchise would pay its employees a different minimum wage than McDonald's Corporate, and Fred's burger cart would still be paying a different minimum wage to his two employees than both. If you find there's some legal manipulation that could go on so larger companies could avoid paying the higher minimum wage, well, then that's no different than every other progressive law on the books.