T.M.
Take 2 days, I don't know about soak city cuz I have not been there in years, but we go to Cedar Point every year and have a blast. The kids will have their favorite rides that you ride over and over and there are lots of shows to watch and its alot of walking so they will be exhausted.
I've never stayed in the motels right at cedar point, I've heard they are very nice but pricey. I've done the camping thing and that was fun. But normally we get a motel not far from cedar point, one that has a shuttle to and from a couple times a day. I wish you good weather.