Vettel imho will have 2 places to go in 2021.
Home, so no more F1.
Mclaren, with the Mercedes engine.
I think Mclaren's (new) atmosphere will do great for Vettel and he can calm down a lot and have a decent car to his disposal.
Mercedes remains a possibility, sure, definately due to his German nationality will be interesting, but, will it still be the team to be at and will Mercedes have interest in Vettel over other cheaper solutions like Ocon, Russell, etc. when Hamilton decides to leave and go for Ferrari, which i still expect to see happening.
For Mercedes, i think they'd concider Ricciardo over Vettel, the bigger question mark is how Ocon will perform against him at Renault, and how Russell will do.
I can see Sainz being replaced in favor of Vettel, and head back to Renault.
well, its silly any way we can take it.
It's funny really, regarding Vettel, whatever he does will be silly.
Staying at Ferrari seems silly (both from Ferrari and Vettel's side) - unless they grab the title in 2020.
Going to Mclaren seems silly.
Going to Mercedes seems silly.
Retiring alltogether seems silly.
No matter what, it will be surprising i think.