We travel with our Golden Retriever and yes it's a huge impediment to your freedom. But then again I will rarely leave the dog alone in the motorhome for more than a few hours and I've never left him in the toad longer than a half hour max and even then only on cool days. So everything we do is dependent on whether dogs are allowed or not. And our dog does very good when left alone. We've never had reports of him barking and he pretty much just sleeps. But I worry too much leaving him along in a motorhome.
Some dogs, especially small dogs, don't like being left alone at all and do a lot of barking as soon as you leave. You may find yourself getting visits from the RV park manager if that happens. I love my dog, but if I were full timing in a motorhome I probably wouldn't want to have one.