Terry
I'll know if the Joker gets anywhere near this building, and Bruce would know if the Joker were anywhere near the Cave. These places aren't just 'home'. They're fortresses when we need them to be and now is one of those times. From what you've said the Jokerz don't hold a candle to the actual man himself, and when it comes to dealing with the Joker you have two people watching out for you that know exactly what they're doing.
You're safe, Bruce is safe, I'm safe, Cass is safe.