How long can you drive with bad CV joints?

Impossible to answer, too many variables. If it has just started clicking when going around corners, you could probably get another 6 months. A big factor is where you are driving. The joint went bad because the rubber boot split and let the grease out and dirt in. If you are on gravel roads much, more dirt is going to get in and it will go bad quicker. City driving, not so much. Let it go too long and it can come apart while driving and very likely tear up something else, probably the transmission. I have seen them break the transmission housing if they come apart and jam up.