Right now.
But that's because it's too expensive to live there, so people move to outlying areas. But if the cost of housing starts to drop, people will start moving in, which will stymie the cost declines.
I'll admit that I'm not intimately familiar with all of the large cities in the US, but Seattle would be a slam dunk. The suburbs are way more populace than the city itself.
Same with San Francisco, although that city has more problems than just a shortage of housing.
I'm not sure to classify New York City, but Manhattan could easily double its bedrooms with no shortage of demand.