like many others, we stay primarily at Federal & State Parks, we have a 29' Class C, that measure 30.5' bumper to bumper, we have a toad on a dolly, we've fit in many sites listed at 30' max. If it's a back in, I either push the dolly all the way to the rear, so that the ramps overhang the back of the site, then back the MH over the tongue of the dolly, or put the dolly off to the side and back the MH overhang off the back of the site, as long as all the wheels are on the pad.
Point is, most public sites are listed as shorter, and you can make yourself shorter to fit, when you make a reservation they ask how long you are, they are normally asking about the camping unit not overall length, mine is 29'. Just don't show up at a 28' site with a 45' Newell. It may fit, it may not.