After spending most of my life in Ohio, and seeing salt damage on my 1st, 2nd, and 3rd motorhomes, I'm very familiar with salt damage. Any road in Indiana you will attempt to drive a motorhome on will have been salted in the last snowstorm. Up north we're very generous with spreading the salt. I would delay pickup of the new coach until at least two rains have passed thru, and the roads have thoroughly washed off and dried. The crushed salt will remain as powder on the roads and sent airborne by air currents from your coach and passing vehicles. By mid-March you may be past the risk of another snowfall, but keep an eye on the Weather Channel. A one-day drive will get you well south of the snow belt. Personally, I would NEVER getting ANY salt on MY new $300+k coach!! After you return home, if there is even a hint of white salty powder on the coach, I would spend a couple of hours under the coach rinsing off everything, engine, drivetrain, suspension, generator, wheel wells. It's the reason many of us from the north will go south to buy our used vehicles.
Kent & Sue & Pecos
2010 Allegro Bus 43QRP
Formerly 2004 Itasca Horizon 40AD