The Wife's Tale by Lori Lansens

Mary Gooch is morbidly obese, and on the eve of their twenty-fifth wedding anniversary, her husband, Jack, disappears, leaving $25,000 for her in their joint bank account. She sets off on a journey to find him, and ends up finding herself as she escapes a weary, confining life in Leaford, Ontario. Lansens also wrote The Girls, which is another of my all-time favorites, and this one is unforgettable,too. Some of Mary's adventures belie reality, but the search she goes on is far more important, what she learns about herself, and how the people she meets shape her new future.