Use it or lose it: How long can you keep Thanksgiving leftovers? Published November 24, 2014 FOX 6 Now Milwaukee Share Copy Link Email Facebook Twitter LinkedIn Reddit Use it or lose it: How long can you keep Thanksgiving leftovers? Use it or lose it: How long can you keep Thanksgiving leftovers? Roundy's registered dietitian, Tatiana Castellino, joins FOX6 WakeUp to talk Thanksgiving leftovers and storage.