Has a course ever been permanently washed away by a hurricane? I wouldn't be surprised if one has, but I'd guess the membership at Seminole has the means and the motivation to restore the course to its pre-storm state (if I were them, I might be out on the course right now taking some very detailed photos, however.)
Augusta National nearly destroys parts of its course every summer, and they seem to rebuild it as good as new, if not better, by the time the next golf season rolls around.