They do sell it, but Disney prices are high. You can walk to Gooding's grocery store in Crossroads center, but they are higher than other stores, as well. Depending upon how many grocery and liquor items you are buying, you may be better off using a delivery service or taking a taxi to Publix.
I looked around gardengrocer.com and downloaded the SSR grcery order form, but don't see "adult beverages". Are they not available for delivery?