The Warriors didn't take on Russell just to dump him later to save money, their ownership is prepared to foot a monstrous tax bill. I agree that he will be available but the Warriors are wanting championship level rotation guys in return, especially wings. I doubt the Warriors would consider Wiggins as that type of player. The Thunder however, would probably be much more open in taking Wiggins back. That's how I would think a Westbrook deal would make some sense for Minnesota. They get rid of Wiggins contract, and while you take back an even bigger one, it also belongs to a guy who's actual an All-NBA or close to it caliber of player.
Westbrook and KAT aren't winning a title, but they probably are pushing for a playoff spot. This won't put them on a championship path, but it would take an absolute miracle for Minnesota to turn themselves into a contender in the near future. For a franchise that's been as bad as they have, there's value in just making the playoffs.