You may not be in the same room right now, but your students can still perform together.
Here’s an example of a dance number from High School Musical captured in individual backyards and living rooms using Zoom. You (or better, one of your students) can use a free video editor like Kdenlive to assemble everything into the final video.
Some other ideas include recreating a radio play or a play involving characters in different locations.
Who says you can’t have fun?