Texas does have wineries!! I live in a dry county, and the only alcohol you can buy in a store is wine made in Texas. Miranda Lambert ( country singer ) has a winery not far from my house... And a Texas wine store.
I hate driving 40-50 miles to buy my beer!! I usually pick some up in Louisiana on the way home..
And yes I-10 is the southernmost interstate that runs east/west. From Jacksonville, Florida to San Diego/ Los Angeles area