I'm not very knowledgable about grapes, but from what I'm reading, the roots should have a sprout with at least 2 eyes. Since you just have roots, you can store them over the winter and plant them in very early spring. Here's how to store cuttings from this site which should apply to the roots you have. Lots of other helpful info on that site as well.
When making your own cuttings, wrap them in moist paper or pack them in material such as damp peat, in a plastic bag.
Keep cuttings refrigerated or store them in an unheated building, in the crawl space under the house. Avoid places where they will freeze. Freezing, per se will not harm them, but can take water out and dessicate them. The ideal temperature is 32-33o F (0-1oC). Properly stored, cuttings can be held for as much as a year or more.
Large quantities of cuttings can also be stored by burying them in pits of sand (to prevent waterlogging) on the north side of a building. They are buried upside down with 6 -18 inches of sand over them, covered with tarps and boards. As spring arrives, some or most of the sand is removed so the bottoms of the cuttings warm and callus in preparation for planting (see callusing).
If you need info on how to grow, trellis and prune: