The blog that I sourced goes a step further though, and throws the grapes in the freezer.
RP servings: I actually cut the recipe down by a ton- it's very scalable. I made about 3 servings worth.
Stars: 4 stars when frozen. They lose a bit of the strong booze taste, and are actually really nice. They also seem more "servable-" when frozen, they'd be a nice bridal shower treat. Unfrozen, you feel kind of like an alcoholic hobo/college student. (Too redundant?)
The marinating wine also gets 4 stars. It was pretty yummy by itself infused with the fresh grapes, but it would also be really, really good with some club soda!