Thea Hvistendahl’s “Handling the Undead,” fresh off its Sundance premiere, has already scared multiple buyers into submission, Variety has found out exclusively. Starring “The Worst Person in the World’s” Renate Reinsve and sold by TrustNordisk, it has been picked up by Hungary (Vertigo Media), Benelux (September Film), Switzerland (Filmcoopi), France (KinoVista), Spain (Avalon Distribution), Korea …