Shelf life of premixed cocktails

On a whim at the store I bought Bulleit’s Manhattan cocktail. It’s not bad, tastes pretty much like a basic Manhattan from a bar. My question is, what’s the shelf life on something like this? It’s 37.5% alcohol which is quite high, but also vermouth doesn’t last very long so I don’t know if I should base it off that turning in the mix? Or will the high alcohol content of the bottle keep it all good for a while?