BLR - we can't let our cats outside here, it's rural and they would be eaten by something fairly quickly. So we need to stay with indoor options.

Right, my cat is an indoor cat. He wouldn't even go outside if every window and door where left wide open. If I lived in one place I'd prefer him doing his business outside, for sure. But in a traveling RV situation, I would be afraid to lose him. So it is a good think he is afraid of going outside, in my case!

That's very true, Jilly - with a normal house a cat has a chance of finding her way home. With an RV that might be really tricky!