OP has said he's a FULL TIMER. "IF" that is TRUE, then he can pick and choose whatever State he wants to declare as his "State of Residency". He could simply choose Monatana and NEVER HAVE TO DO THE LLC thing. Save money, hassle, insurance etc. That said, he could do likewise with South Dakota, Texas, Florida etc.
The only difficult part is establishing your "State of Residency". The IRS will look at your INTENT when declaring your resident state. Transfer your bank accounts, insurance, voter registration, driver's license, vehicle registration etc. and it's a done deal. It's easy but time consuming.
We use Americas Mailbox in Box Elder, SD and they take care of everything except your driver's license which you have to do yourself. There's no test etc involved if you have a DL from another State. Take your valid DL into their office and they print out your new one on the spot. Good for five years before you have to return to renew. Only requirement is an overnight stay in SD. Americas Mailbox has a campground on site to satisfy that requirement. If you don't want to take your rig to SD, fly in, rent a car, they have rooms for rent at their facility......Dennis