The current European wine production is 15 billion liters per year. Divide that by 365 to get production per day, and by historical population estimate for 1600-1799 (roughly 120 million) and you get a production of less than half a liter per person per day. To come to a figure of 7-9 liters per person, you would have to increase yield twenty-fold. Current European wine production takes up 30.000 square kilometers. That means that even with modern yield rates, a figure of 7-9 liters would require more than the entire arable land surface of France.