I think that for not many more $$ there is Coastl Georgia RV Resort on the same exit you use for Blyth Island SP.

Coastal GA has all pull thrus, roomy, neat, amenities, etc.

We stayed at Coastal GA in Feb and toured Blyth Island. While we like the camping type atmosphere of the State Park we thought that, for our rig, we'd have to choose wisely when picking a site. It is all wooded and some sites looked there would be no way we'd try them

Also on the same exit is Southern Retreat RV Park. I can't recommend that one (and have stayed there in the past).