Honestly, Cedar Point is no where near as "Pooh Sized friendly" as Disney. We live just 45 minutes from the Point and we go frequently since we have season passes. I am a 2x and there are some rides I just cannot fit into. Top Thrill Dragster and Millenium Force are two of them. I can do Raptor but it's tight, as in the ride host shoving the seat down on my chest tight. I can comfortably fit into Maverick. I haven't done Wicked Twister because DH is too tall for the seats but I did fit in the test seat although it felt much like Raptor. I also cannot ride the Blue Streak anymore since they went from a bench seat to individual seats on the bench. I can't speak to Mantis or Mean Streak since they are both too rough for my liking. Some of the smaller coasters are just fine for me like the Cedar Creek Mine Ride, Corkscrew, Disaster Transport, Wildcat and the Magnum, which is my absolute favorite.
As for the flat rides, I haven't found anything that I haven't fit into. I did just fine with Sky Hawk. Some of the kids rides are tight but most of the time they are accomodating so that your child can ride. As a PP said, if you are unsure about a big ride, most have test seats you can try. And if you head to CP, have a wonderful time. I can't wait until we can get to the Point again!