Well, I guess if you can get the head gasket done on warranty/recall, the service people will be able to tell if more damage was done.
You said you had it towed when the overheat happened. How far would you say you drove it before you noticed the problem? I am willing to bet the engine is ok. The head will probably need to be reworked when they do the gasket. The big problem with the job is not pulling the head, but the fact that I believe the engine has to be removed to do the work.