On Thursday at 7 a.m., Hoda Kotb welcomed viewers to NBC’s “Today” show, as she does every weekday morning. This time, however, she was alone at the desk, without her co-anchor.

“We are so happy you are with us this morning, and like a lot of you, we are all kind of adjusting to our temporary new normal,” she said. “I’m in Studio 1A. Savannah Guthrie, you are …?”

Ms. Guthrie appeared on half of the screen.

“At home,” she said. “At home once again.”

For a second straight day after reporting cold symptoms, Ms. Guthrie was broadcasting from a basement in upstate New York. The three-second delay separating Ms. Kotb’s question and Ms. Guthrie’s reply gave the impression that she could have been thousands of miles away.

Even in bad times, viewers depend on the feel-good presence of “Today,” “CBS This Morning” and ABC’s “Good Morning America.” But as New York City, where they are taped, became a hot spot for the coronavirus, the programs were challenged to keep up their usual good cheer and show-must-go-on spirit.