Any website that shows rv parks along my route?

You do not have to be a member of Passport America to use it's routing which has the option of adding their CGs along your route. Since it's going to happen in the afternoon in the East I'd head toward a rural area and stay at a CG several hours outside of it's path. Drive to near the center of it's path in that area and park your C on the side of a farm road...drive back to your CG afterwards.