Leaving it drip in a house will save the pipes, but house pipes are much better insulated from the cold than your hose can possibly be just laying on the ground. It also wastes a lot of water, which is not a good thing to be doing in general, let alone in an arid area such as central California. One might do it in a house due to the complexity of adding insulation and/or heat tape to pipes in a wall. But it is just plain wasteful (as well as possibly futile) for a hose on the ground. The large mass of water in your fresh tank won't freeze unless it drops below freezing and stays there for several days.