For cars like that, I don't care if your vacationing in Europe. You call a towing company, you call a locksmith or a trusted neighbor with a key to get in, and you have the cars towed to a secure storage facility that is outside of the hurricane zone. So it costs a couple thousand dollars. That's what you have to do to protect cars like this. When you are the overseer of important, historic vehicles like this, you have a duty to protect them.
I remember reading something from haggerty insurance that says they'll even cover the cost of moving your car if it is insured with them and a hurricane or other natural disaster is imminent.