Well, at the rate Max, Bernie and associates are spewing out insane ideas and rulechanges, I don't think we'll need to worry about Ferrari leaving F1.
I think F1 will cease to exist well before that happens. I'm having flashbacks to the old CART days and the split with the idiot grandson (Tony George, FYI). It took 13 years of failing seasons and the total destruction of what once was the greatest motor race event of the year, but the IRL has finally won the battle for American Open Wheel Racing... And what happens? Nobody watches it, the Mindy 500 is only watched by people outside of the US who have no idea of what happened, and the Idiot Grandson has finally given his 'vision' 4 years before he pulls the plug entirely.
We don't need to worry about that happening with F1... I'm thinking they'll put it out of its misery in 2 years, 3 tops.