We have a Goldendoodle that travels with us. He rides on the back seat of my F-150 super cab. We have a board and cushions for him to ride on. He is a fairly large dog.
It is rare that he does not go with us but when he must be left in the TT, he sleeps on the couch until we get back. He also sleeps in the truck if we go somewhere for a hour or so.
A major setback is the National Parks rule which will not allow dog on the trails. We have had no problems at the various State Parks; he even goes with us on group hikes as he is a people dog, waiting for the next person to pet him.
My DW will look for "No-leash Dog Parks" or we will ask the camp manager if there is an area "out back" where he can run.
We are going to do a trip to Glacier National Park this summer and will stop at several other National Parks on the way back. For the first time we are going to leave him with my daughter and her dog.
It is a tough call but probably better for the dog on this trip.