Malcolm Kutner, a Manhattan designer, also started before Thanksgiving to help a German client decorate her second home, a 20,000-square-foot triplex loft, for both holidays. “It’s very themed and schemed — very funky with pine garlands and gourds that we spray-paint in silver and gold,” Mr. Kutner said. “It’s very collaborative; she gives me a shopping list of what she wants to work with, and I make it happen.”