As her family drove down the Long Island Expressway, the now 78-year-old imagined then that every car on the road was headed for her grandparents’ home. It was a yearly chance to see the extended family and connect over a millennia-old ritual. For around a decade, she’s carried on the Passover tradition — albeit, with a smaller crowd — at her son’s home in the suburbs of Boston, joining his wife, his in-laws, and Hornfeldt’s grandchildren. Susan Hornfeldt remembers the crowded table stretching from wall to wall at the Passover Seders her grandparents used to host in their Brooklyn apartment...