You really need to consider how you are going to use your RV.
Are you going to spend entire days sightseeing and such? Or will you spend the majority of time in the outdoors?
Next consider where you want to stay. As mentioned, RV Parks often have bans on breeds and/or large dogs. National parks don't allow dogs anywhere but paved roads and the campground, and they don't allow you to leave your dog unattended. USFS, COE, BLM, and BOR campgrounds are usually the most lenient - allowing dogs on trails, but rarely have hookups.
I camp with two large shepherd mixes. I rarely stay at RV Parks. I don't use day care or sitters - I won't leave my dogs with people I haven't been able to fully vet. I will be going to Death Valley soon. I contacted the park to ask about specifics. As I will be going during the cool season, it is OK for me to leave the dogs in the suv while I walk a short trail, etc. If I couldn't do that, I would not go at this point as I would be very limited on what I could do and see.
If I didn't already have dogs, I would wait. I would go to the places that are not dog-friendly first. Once,I'd done that, I would get the dog and then limit my trips to dog-friendly places.