When summer starts receding, the string of picturesque seaside communities that make up the Hamptons on Long Island’s South Fork traditionally begin retreating to their small-town roots. The cooler and calmer months of fall bring with them a slower pace. That shift in tone certainly won’t defer Mimi Ritzen Crawford from the manicured two-acre property she owns with her husband in Southampton, New York. Though the vestiges of summer abound at her 8,000-square-foot residence—a heated gunite pool and grass tennis court sit on a plot just half a mile from one of the most private stretches of beach in the Hamptons—Ritzen Crawford isn’t abandoning her bountiful amenities when the weather…