In my opinion Kakashi can win this. He is a really smart Shinobi and has a powerful MS that if landed is fatal.
Kakashi is known for using substitution and kagebushins for as long as it takes to gather enough information on how to kill his target so that will buy him enough time with not much chakra to ruin while others fight each other in the battlefield with the ones being exhausted first Darui and Mifune because the others have some great defenses. Notable is the fact that he has an upper hand on Gaara and Kitsuchi because of his Lightning Style. Both Gaara and Kitsuchi have got better defenses than abilities to kill so If Darui and Mifune die from exhaustion or Kamui then it's kinda on Kakashi's favour to win the match.
Darui could be a possible alternative because he manipulates those Black Panthers so well and his Black Lightnings can without much difficulty defeat Gaara and Kitsuchi. Kakashi vs Darui battle would be awesome, but Kakashi should be the winner if both have same chakra left though and if Mifune hasn't done much on Kakashi which I doubt.
All in all, I believe Kakashi would win this fatal deathmatch, but ofc no one can be sure. =]