Purchased new motorhome online, help with title questions

I think you're being a little too paranoid. If it's through an established dealer, I wouldn't worry about it. They have to take the title into the DOT, pay the taxes/transfer fees and (possibly) get new plates just like a car dealer. They will provide you with new plates and the state will send you a new title in your name. In the meantime, you'll have a bill of sale which establishes you as the legal owner.
If it's just an individual, I'd require a title in hand - but not a dealer.