I would say you'd be fine to use it now. All the gelatin does is attract the large proteins still in suspension clouding your beer, and it settles to the bottom after coagulating. I'm sure you can just toss it into your lagering carboy at any point, it won't affect the taste at all. If you're kegging then you can even throw it into the keg. Otherwise siphon your beer off the carboy when bottling and leave your gelatin at the bottom.