Well, with Madara now controlling that part of Obito and looks like its spreading through his body, no chance unless Obito takes one for the team and lets Kakashi or Naruto kill him, but I don't see Obito being "good".
Madara is using Obito, just like how Obito was using Madara when the were on the Juubi and still connected.
That's why Madara was somewhat compliant with Obito's words, he had this Ace in the Hole.
Also if Kakashi got the other Sharingan, like you noted, he would run out of stamina twice as quickly and might go blind.