I'm sure that, in the years since the original article was written, the stores and vineyards have developed some more sophisticated methods and packaging for shipping cases of wine to other states. As of about two years ago, the last time I was there, it was still possible to ship from at least some of the Napa wineries and stores.
I have, however, failed to pay attention to what shipping agencies they use. There may be a number of companies that handle this type of traffic now.