A CDL is not going to help... might even hurt as harder to plead ignorance of the law. I'm sometimes a lot more than 2' over and have never been stopped much less measured. I am surprised how many states there are with 60' or
less. Once you get to an Interstate Highway you are legal.
While we RVers are special, we are not exempt from the various state laws (when on state highways) even though we are not a commercial vehicle. Are we ever stopped and measured... rarely and reciprocity does not apply to length.