Winery country visits are not all about eating and drinking right? If you have the time you should spend an hour to two working off some of those calories and in California that is generally easy to do.
Just to the south of Livermore one finds the Del Valle Park. A lovely and fairly pristine expanse of rolling hills surrounds Del Valle lake where you can take off for a leisurely hike, dip in the lake or even rent a boat to explore the placid waters. You can even take in some fishing, the lake is stocked with trout and catfish. What a lovely day you can have in Livermore. Visits a few wineries, take a walk around the lake, dip a pole and hopefully come up with some trout for dinner. Perfect with the local whites, and for capturing the essence of this undiscovered region!