We travelled with our 3 adults and a medium sized dog...She curled up close to the dinette...she had to move if someone went to the washroom during the night but other than that no problems...
Dorothy and Mike
We were camping at Englishman River Falls on Vancouver Island last summer and the couple next to us had two cats with them. They had some kind of large enclosure system that the cats could move about in. Did not see it up close so not sure of the details of the enclosure.
I guess it depends on how well the cats travel in a vehicle. Our cats never liked the vehicle because they knew they were on the way to the vet to get poked!