What Real needs is a young striker. Karim is old, and getting another old striker in Cavani is not really a good thing. Now, if they can get someone in the likes of Dybala, Pulisic or Draxler, they can move Ronaldo to the striker position and either Pulisic or Draxler takes the wing. If they opt for Dybala, then he can be the perfect receiver for those passes.
With the way that Harry Kane is performing I will not be surprised if Real Madrid eventually table a world record fee to tempt him away from Tottenham Hotspur, I am sure that they wouldn't hesitate for even a second when a bid of 300M Euros is launched by Florentino Perez.