17 meter Edge or 19 if you are a bit more rotund, I see the race board guys getting their edges up in 6 knots and whith race board or foils can get going upwind no probs. Or you could use a large surfboard maybe??
Generally I do not like kiting in light wind - but the new kites especially the ozone edge and race boards are changing that for sure.
Big tip is keep your kite high as you can not low on the edge of window and definitely out of the water in light conditions. Otherwise crack a few stubbies and go out the next day when the wind is stronger