Dec. 16, 2020 Lourdes Lopez, the artistic director of Miami City Ballet, is facing a new unknown. It’s a fear she’s never had. And it stresses her out. “I just hope that at the last minute that they don’t close us down,” she said. It’s no surprise that she has been wondering what it was like to run a ballet company in London during the Blitz. Against the odds during a pandemic, the company will present its reimagined production of “George Balanchine’s The Nutcracker” this month. Normally, Ms. Lopez said, her worries would fall more along the lines of, are the costumes going to be ready? Will an injured dancer recover in time to perform?