Only you know how your dog does in the car so that part only you can answer.
However, I can tell you we take our little yorkie with us everywhere we go. We have a 5th wheel now so we don't have to worry about hotels. Before we got the RV, I always checked along the route and at our destination to make sure we had a dog friendly place to stop. With the RV, neither the dog nor I can travel much longer than 2 to 2 1/2 hours without a stop. Our truck really beats me up so I have to get out and walk around. She does o.k. on road trips, if we are on the interstate she will pretty much just sleep in my lap. If it's country roads, she wants to hang her head out the window. Rest stops are your friend. If we plan on doing any kind of going out and seeing things, we only go places that allow dogs. Most cities/towns have some dog friendly restaurants - which means you sit outside. We did find the trolley tours in both Savannah and St. Augustine are dog friendly (at least one of them is) so we took her on those. We also found a beach in St. Augustine and on Jekyll Island that were dog friendly but she hates water so won't go even close to the ocean. We will leave her in the RV for about a hour if we want to go out to eat and did leave her in there for about 4 hours while camping a WDW. When staying in hotels, we never left her any longer than it took to go to the onsite restaurant to eat. We do a lot of hiking and walking around towns outdoors, if one of us wants to go into a store, the other stays outside with her. I do have a carrier for her that I can wear and there are a few places we have found that will let her in if I'm carrying her.