As the weather transforms in May, so do the wine offerings, morphing from winter warmers into bright, refreshing whites, rosés, and sparklers. But we haven’t overlooked the reds, with a bevy of great options from around the world to suit every palate. This month, we took a dozen top Sauvignon Blancs from Marlborough, New Zealand for a test drive, revealing an eye-opening range of styles and quality levels. We also tasted eight of New York State’s top Cabernet Francs, discovering a lot to love among…