outdoors! or a really well ventilated environment.
But you also have to consider the cards are really good fomites and if one of your players is infected virus can be loaded on the cards. So you have a problem there.
Now, you could only be infected if the virus was on the cards and then someone touched their mouth, nose, or eyes. But that is a fairly common behavior that takes a lot of training to stop. I am not sure what to recommend here. Sorry!
We play with couples locally and other cities by use of BridgeBase. See BridgeBase.com