We travel with two cats. We hve halters and leashes tht we use only when transporting them from the car to the trailer or vise versa. We use a carrier to transport them but they have a leash on just in case the get out of the carrier.
My cats are very curious and one really wants to go out. Unfortunately, almost anything frightens her so I am certain it would be dangerous or ,like above, she would just hide in fear till...
We are snowbirding right now. We also have a small dog and due to other campers not keeping their dogs on leash, it is difficult enough keeping her safe.
Out cats stay indoors. Sometimes you just have to make the decision that is best for them but not necessarily what they want.
The only thing that I have seen is someone had rigged a wire crate to a baggage compartment. The cats could lay out in the cage or go back inside via the baggage compartment. At least this way, if something frieghtened then they could run to cover.