In Canada, free universal healthcare is only available to Canadian citizens or permanent residents. As Lisa Simpson is neither, she would have to pay a hefty medical bill for her hospital stay.
During Homer's "Upstate New York" song he drinks with the Headless Horseman of Sleepy Hollow. Sleepy Hollow is in Westchester County 25 miles north of New York City and over 100 miles away from the other towns referenced in the song of Niskayuna, Utica, Oriskany and Buffalo.