Probably closing their KH and making them drive inconveniently further.
Wouldn't that make the Zoom situation even worse?
The only thing I could see them doing was suggested by someone else previously: withdraw the right to connection and make it something subject to 'approval' by the elders, for 'genuine' cases of sickness or infirmity.
The problem with that is, once someone has the code, they could continue connecting even after they've recovered. Or they might share the code with others in the congregation. So the elders would have to keep changing the login details. It would create a lot more hassle for local congregations.