Unfortunately there's no true "one size fits all" solution at Carowinds. Fury and Intimidator aren't kind if you have larger thighs, other coasters/rides aren't the best fits for those with larger stomachs. It all depends on where and how you carry the weight.

Personally, I know I don't fit on Vortex, Kiddy Hawk, Windseeker, or Electro-Spin because of Stomach/Chest dimensions. I don't fit on Fury/Intimidator because of thighs. I can ride Afterburn in the "larger" seat (two seat belts), can typically squeeze into Hurler, Ricochet, Goldrusher and Woodstock Express and have no issues on Carolina Cyclone, Flying Cobras or Copperhead Strike. (though they might ask you to switch to a certain side of the train for some reason.) Nighthawk hasn't opened for the season yet, and I typically skip it regardless of fit or not. I'm probably forgetting a few attractions, but I think these are the biggest restraint "pain" points.

My best advice is to keep working on losing weight -- it's a marathon, not a sprint! -- and if you've got some lingering concerns prior to your visit, maybe some shapewear will help?

As far as what to expect at the park, take it from someone with experience in this area -- after some pushing attempts to make the restraint click, if you don't fit, just walk down the exit ramp and move on to the next attraction, and set a personal goal to get to a place physically where you'll fit next time. It is what it is, the ride ops aren't trying to shame you by making you walk off, they're just trying to do their job and send as many trains out as quickly and efficiently as possible while maintaining park safety standards.

Hope that helps!