Cleveland to Pigeon Forge TN is just under 9 hours (3 routing possibilities come up on Google Maps). Dollywood is a very family-friendly place to go. Lots of other shows and activities in Pigeon Forge. Just minutes down the road, you can visit Great Smoky Mountain NP, and maybe go as far as Gatlinburg.
Niagara Falls would be a reasonably short drive, but you may have already done that. Adirondack Mountains (upstate NY) has all sorts of things to do (or at least did decades ago when I grew up in Buffalo).
SKP 115048
2016 Winnebago View 24M
2015 Harley Heritage Softail as toad
Retired:
2007 Titan LE with the Big Tow Package
2010 Rockwood 8315BSS
2008 Suzuki GZ 250-Response to 3/4 Life Crisis :C