You can actually find lots of rental properties in Sandusky close to Cedar Point. Unfortunately I think most of them are a week minimum rental and they fill up really fast.
I can tell you from experience that the Microtel is not too bad. The pool is open 24/7, they have a continental breakfast and it takes about 10 minutes to get to/from Cedar Point. That is generally where we stay when we go. Not sure if we will this year again or not, because I haven't seen their prices drop down like normal for summer time vs college student time.
BTW - Cedar Point is really kid friendly.
Oh and another option to look at is renting a cabin or cottage on property. It has a stove/fridge etc and easy access to CP.