I cannot see Hulk returning to Renault, why would they want him? Alonso returning is the most likely scenario and he has apparently already agreed personal terms with the team. Vettel will either retire or replace Bottas at Mercedes. I think Mercedes know Vettel cannot match Hamilton over the course of a season. On the other hand, neither can Bottas so hard to see what they would gain from the situation.

Vettel to retire is the most likely scenario in my opinion.