For decades Ethel Davis Hopper, known by "everyone" around town as a poison-dripper and a control freak, has hosted family reunions in her little slice of beautiful northern Vermont for what has burgeoned into five generations of Davis and Hopper offspring. This year's reunion will be different, though: she's planning to host her own living funeral.

The extended family, described by Ethel's favorite granddaughter as people who cluster themselves in three factions, "like bunches of Sunnis, Shias, and Kurds," plans to gather at Ethel's dream home overlooking the quaint village, despite their...