Travels with My Aunt (1972) on Netflix

At the funeral of Angelica Pulling in London, her staid, straight-laced and joyless banker son, Henry Pulling, and her eccentric sister, Augusta Bertram, ostensibly meet for the first time. Henry had heard stories from his mother about his Aunt Augusta, who he had assumed had long passed. Information from Augusta about his "mother" and an action by Augusta's Sierra Leonean friend Wordsworth convince Henry to agree to Augusta's request to accompany her on an imminent trip to Paris, despite Henry never having done any international traveling. It isn't until they are well on their way that Henry learns that the purpose of Augusta's trip is not to sight-see as he had assumed he would do, but rather to save the only true love that she has ever had in her unusual and unique life, an Italian by the name of Ercole Visconti. As Augusta's task takes her and Henry far beyond just Paris and as they get into one adventure after another in Augusta's often less than above board actions, Augusta and Henry will either be torn apart by their fundamental differences, or brought closer together as they begin to understand the need to be a little more like the other, the only real family they have left in the world. For Henry, what happens is also the result of coming to a realization of what Augusta's information about his mother and father really means.