My own 2 cents. Get an older dog, one that is already house broken, done teething, and settled down. It's hard to deal with a rambunctious puppy in the confined space of an RV, so give an older dog a chance. You'll know how big it will be and can get an idea of its general character. Research breeds. Don't just go with a dog because you like how it looks. Temperment is much more important.. Is the breed easy going, or high strung and yappy? Tolerant of people and other animals or likely to bite? Is the breed calm and confident, or likely to get upset by changing surroundings? It takes some hard nosed research to get a good canine camping companion.
We always get rescue dogs. Puppies are cute - in someone else's house. I don't like the mess of housebreaking, having my stuff chewed up, and dealing with the energy level of puppies. Fortunately for me, but unfortunately for the dogs, there has always been a steady supply of adult dogs to choose. Barney, the little terrier thingy, was small, slowed down by a leg injury, and quiet - the perfect companion for my disabled hubby in a 32-ft travel trailer. When we got the house and fenced yard, I got my Jack, the gentle, easy going Bernese Mtn Dog. With Jack gone, hubby came home with a happy, friendly, highstrung lunatic of a bichon. Hubby should not be allowed to pick out dogs by himself. We will see how this one does on the road..