It's gotta be Point or Sergachev.
If it's Sergachev, maybe Miller goes to Ottawa as well. Miller and Callahan are the only significant Lightning forwards with cap hits that don't have full NTCs. Taking on Callahan's full cap hit would be out of character for Ottawa. He's still owed 4.7M for two seasons and only had 18 points last season.
Sergachev has two more years left on his ELC, point only has one year left. With Stralman and Cobourn likely leaving as UFAs after a Karlsson acquisition due to the salary cap, maybe that makes Sergachev more valuable to Tampa than Point. I don't see Tampa giving up both Point and Miller to Ottawa, their offense while still amazing would take a big hit. Tampa could still trade point after the season before his NTC kicks in to clear cap and benefit from having him for the entire 18-19 season.