I think most tire manufacturers recommend a competent inspection (which involves unseating the tire and inspecting the inside as well as the outside) annually after about 7 years and replacement if they show signs of needing it during inspection or unconditionally at somewhere around 10 years. Often, especially for less expensive tires, the cost of inspection is close enough to the cost of new tires that it's questionable whether it's worth doing vs. just replacing.
Tires (and batteries, for that matter) last noticeably longer in northern climates than in hot southern climates. I would not personally have any hesitation with using seven year old tires on a vehicle stored indoors in New York if they seemed to otherwise be in good condition.