I would use google to see what wineries don't add additional sulfates. (Grapes/wine naturally have some level of sulfates). The added sulfates usually come from using them to stop mold growth in a vineyard or as a preservative in the wine.
Anyway, once you find out what wines don't add sulfates or are organic then see if they appear on winelists at WDW. I learned this:
The level of sulfites in wine is measured in “ppm”, or parts per million. In the United States, conventionally made wines are permitted to contain up to 350ppm of sulfites. Organic wine-making typically limits the threshold level of sulfites to 100ppm, and levels are generally much lower (around 40ppm to 80 ppm).