Rockefeller Center is preparing to open its first hotel, the latest sign that Midtown Manhattan’s largest office landlords are leaning into hospitality and entertainment as remote work reduces demand for office space. Aspen Hospitality plans to convert 10 floors of vacant office space above the NBC “Today” show studios into a luxury hotel. Rockefeller Center was a natural choice for Aspen Hospitality, because its owner, the Chicago-based Crown family, co-owns the complex with New York-based real-estate developer Tishman Speyer.