Hmmmmm. Depending where exactly they live in Fairview park, I/90 to Route 2 may be a more direct and tool free route. I-90 Branches into the turnpike/I-80 heading west, but splits into route 2 which runs north and is a straighter approach to CP than the Turnpike. Route 2 has a speed limit of 65. What I do is get off at the Rye Beach Road Exit and take an immediate left onto Cleveland Street were the Speed limit is 55 until you get close to CP. I think it a heck of a lot faster than driving through the more congested parts of Sandusky via 250. It takes me about 50 minutes to get to the point from the West side of Cleveland using this route. Also if you arrive near opening and take this route, it would be a good idea to take the chaussee (sp?), or Cedar Point Drive. They took the signs down for it, but is easily recognizable when you see a mess of branched roads running into Cleveland Street. It can save many a minute from waiting on the Causeway to get to parking booths.
I'd expect moderate crowds. Actually one Friday I went no to long ago the park was empty, so good luck!