spring break destination suggestions?

I'm going to Charleston SC but that may be outside your driving range. It is a great place to visit.

Hot Springs Arkansas. We like Catherine's Landing RV park. Lots to do in the area. Milder weather (usually). 700-750 miles from Chicago.

We have done Memphis for spring break several times. We always have a good time there and the kids 8 and 15 actually do like going to Graceland. The zoo is really good there as well and the BBQ, well that speaks for itself.

Myrtle Beach is about 900 from you Lots to do for kids and adults and lots of places to stay in RV.

South Florida. If you want to avoid spring breakers, pick smaller parks away from the coast.

Since winter is a bit long this year and depends on when your spring break is (March or April). In April you can probably get into the Smoky mountains or other areas in the higher elevations.

To be more sure of nicer weather in March you'll need to head to the lower elevations and as far straight south as possible. I'd choose Branson; Memphis; Nashville; Lexington, KY (Kentucky Horse Park); Renfro Valley, TN; just give up and head down to Lafayette, LA (Tabasco Factory and more) or Mobile, AL (Naval carrier USS Alabama).

If we should have a rough spring storm season there is no telling which area will be best.

And it depends on what you want to do while on vacation. If you go too to the normal college kid or family destinations you will find they are very busy.