You are own your own......your loss. Neither consignment or insurance will help now.
They might not be inclined to pay, but that doesn't mean that is the law in the OP's state. Some states are quite restrictive about what legal rights can be waived, others not so much. It's fairly common for jurisdictions to allow ordinary negligence to be waived, but not gross negligence, so the circumstances could matter. Did a thief climb a locked gate and hot wire the RV or was the gate open, the RV unlocked, and the key in the ignition? Might matter a lot. I strongly second the suggestion that the OP consult an attorney in his state who is knowledgeable in the area or willing to do a bit of research.