We'll see what happens, but the budget is extemely small and I'm trying to figure it out as is. To really light the vineyard with the moon you'd have to bring out the big guns and I just don't see that happening.
The other option floating around is doing the scene at sunset/magic hour, (which I'd like to do) but it's a long scene and we won't have the days.
A little more detail about the scene: It's a shootout, for lack of a better word, and the sense of confusion and not knowing where anyone is will work. The 2k will be about 12 ft off the ground and is really just to get the actors into the vineyard. Once they're in, it'll all be silhouettes, closeups, sudden appearance and disappearances, quick shots of someone running here, a dive to the ground there.
The idea of hiding a few lights around the vineyard has been thought about, but it just doesn't make sense for the location or story. Though maybe a single light at the other end of the vineyard (as another "security light") might work, and give some depth.