Freezing prepared dry salted fish
For freezing the desalted cod, see one of the answers to this question.  Apparently frozen, desalted cod is a common supermarket ingredient in Portugal, which suggests that it's as good, or almost as good, as &quot;fresh&quot;.  This is not a surprise, since salted cod has already been dehydrated once, so a trip through the freezer is unlikely to hurt it any.
For freezing the whole recipe: yes, I'd expect that it would freeze well.  The cod will freeze fine, and tomato sauces also freeze well, so I'd expect portions of the finished dish to be a good keeper.