The Doloriad by Missouri Williams

In the wake of an environmental cataclysm, the Matriarch and her family cling to existence. The Matriarch, ruling with fear and force, dreams of starting humanity over.

Surrounded by the silent forest and the dead suburbs, they scavenge supplies and attempt to cultivate the poisoned earth, brutalizing and caring for one another in equal measure. For entertainment, they watch old VHS tapes of a TV show called Get Aquinas in Here, in which a problem-solving medieval saint faces down a sequence of logical and ethical dilemmas.

One day the Matriarch dreams of another group of survivors, and sends away one of her daughters, the legless Dolores, as a marriage offering. Dolores returns and triggers the breakdown of Matriarch's fragile order.

As the children seize their chance to escape, the world of the television saint Aquinas and that of the family begin to melt together with terrible consequences.