Gulpha Gorge Campground, AR

Would like to stop at Gulpha Gorge on our way home from Grand Isle SP, LA and wondering what the odds of getting a site for a Friday & Saturday first full week of May. They do not take reservations and we really liked the park when we were there several years ago. Or do you think our odds would be better if we tried for Sat & Sun. Just can't get there before Friday.
Any thoughts or predictions? Or also plan for an alternative, just in case? And that would be where?