Earlier this season, in an unprecedented event in Big Brother 22 is even going to happen this summer.
Big Brother Canada 8 had to be cancelled due to the virus' potential effect on production. Everybody in the game was placed in the house before the virus spread, so they were safe. The worries were about it spreading between people who work on the show, and ultimately the show just wasn't an essential business that needed to continue despite that. Certainly right now, Big Brother US could not avoid similar issues. It wouldn't be safe to work on the show, finishing up casting soon would be difficult, and it doesn't even have the aspect where the players were already quarantined in the house. If the pandemic situation stays consistent through June, when a Big Brother season generally premieres; then at the very least there will be delays.
Big Brother is not a particularly expensive show to produce, and being on three days a week, it fills up a lot of time in CBS's schedule while always maintaining decent ratings. It's no secret why it's still airing 21 years after it began. CBS wants the show to continue, so the network will be playing it by ear and adjusting; however, the question is just to what extent. How much can a season be delayed before it just gets officially pushed to the summer of 2021?
Delaying the infamously maligned season by fans, but still it's evidence of the show being flexible and used in that way. Due to that, the adjustments made should the pandemic cool down within a few months could be a season running shorter than recent ones, having the show continue airing further through the fall than usual, or even pushing the season far enough to be a full winter season.
Production companies are still playing a lot by ear, so there's very little to be said for certain. Ultimately though, Big Brother is a very flexible show that has had seasons outside of its regular schedule as well as many spin-off seasons. With other popular reality shows like Survivor having their next seasons cancelled, there will be plenty of hours needed to fill on nights at CBS. The pandemic might not end soon enough for Big Brother 22 to air in the summer, but if that's the case, there are still so many other opportunities for it to air that it would be surprising if the 22nd season doesn't come at some point before the following summer.