My recommendation is to contact the state patrol for each state you will be traveling through and ask them specifically your questions.
Someone posted on a Facebook group about triple towing, that a state patrolman told them somewhere that if it was legal in their state of registration, then it's good everywhere. Which is false. And to confirm that, I went to the NC State Patrol page and sent an email asking. I received a
response with the statutes listed on triple towing and that you must follow the rules of the road for the state while you are in it, no matter if you are from Florida, Washington, California or whereever. LEO's do not keep up with the laws of all the other states (exception of things like reciprocation of gun laws, etc). Especially when it comes to the road.
One thing to remember as far as where you get your information, is to think that if you got a ticket for something and had to go to court for it, what would be your defense? That Bobo on RV.net told me or that the xyz.com website said I could? I would like it printed from an official of the state or an official printing from the state that states it. And you need to make sure that the printed material from the official or the state is current. I wouldn't try to go by something from 1982 or something. Something that was updated in the last few years. Just my recommendation as an LEO. It's up to you (the traveler) to know what the laws are, even if it's another state. Does it happen? No. But all you need is one time. We here all kind of whacky stories here on the forum as it is. It can happen.