The route is flexible to and from Chicago.
Rick, We have stayed at the Apache CG in North Myrtle Beach, liked it, many seafood places, we enjoyed the music at some of the theaters, think bikes would be OK for most, but I have no experience there with bikes, would contact the Camp Ground to see about the length, might not be an issue IF your used to handling it in tight areas.Good luck and have some type sun screen.Dave M
I was going to suggest driving up the Shenandoah Valley for a ways on your route north. It's lovely, very historic, and relatively flat and you do it off the interstates. I kind of start around Greensboro NC and go north up Hyw 29 aways. It's kind of out of the direct route to Chicago, though.Brian
If you go north from Myrtle when you get to the outer banks you will have to cross some water on ferries. You might want to check to see if they have a length max. I do not think you will have a problem but I would want to check first because if you have to go around them it is a looong way. If you can fit on the ferries it is a wonderful area to see. I have done that trip in a car and went on up through Williamsburg Va. As far as camp grounds in Myrtle Beach with kids you cannot go wrong with Ocean Lakes. They can probably get you a pull through so you do not need to unhook and the kids will have a lot to do there.