When Theory Wellness opened up shop in Great Barrington in 2019, it became the first recreational (adult-use) cannabis dispensary in Berkshire County. Unlike most businesses that opened a year before the pandemic began, they posted enviable revenue numbers from the start. Since then, the cannabis market in this area has exploded, and a town that’s home to less than 6,000 people is earning millions in tax revenue from the boom. Most people would agree Great Barrington, MA, doesn’t have the climate for growing cannabis. Its winters challenge the hardiest of plants with a wicked freeze-thaw cycle and an average low…