Is A Full Return To Formula 1 Off Of The Cards For Fernando Alonso?

McLaren has just signed a deal with SPM which allows them to compete in a full season of IndyCar. You could say the most likely candidate for a driver is Fernando Alonso. If he has been offered a drive and has accepted it, this would mean that it would be impossible for him to do a full season of F1, which many of his fans are pleading him to do. Would the Spaniard accept the drive?
After this years disaster trying to qualify for the Indianapolis 500, would Fernando compromise a whole year of his racing career in order to win just one race? I personally think not. Alonso has made his intentions very clear. He does not want to spend time growing a team and trying to make it successful, instead, he just wants to drive a car that can win immediately.
What are his options in F1?
Alonso is very limited to who he can drive for in formula one as only three teams can realistically build him a championship-contending car, two arguably.
Ferrari - They have what many believe to be the next world champion Ferrari driver, in Charles Leclerc. I don't think that even Fernando Alonso could steal a red seat unless Sebastian Vettel retires at the end of the year which looks highly unlikely as the German has already denied the rumours.
Mercedes - The Finn, Valtteri Bottas has an uncertain future at the consecutive (and as things look soon to be 6X) 5X constructors champions. Two things have been made clear by the team principal, Toto Wolff. Its either Valtteri Bottas or Esteban Ocon. Let's throw a spanner in the works and pretend that by a miracle, Alonso takes the seat, this could easily cause havoc with teammate Lewis Hamilton which is what happened at McLaren in 2007 when the two champions were working together. This can almost certainly be ruled out especially as Hamilton has just stated that he will not be retiring anytime soon.
Red Bull - Verstappen is very happy at the team after winning two, almost three races this season already! Pierre Gasly has been clearly underperforming and could be out for next year. I'm afraid to say we won't have a Verstappen Battle VS Alonso because of the engine partner, Honda, that Alonso burned his bridges with between 2015-2017.
IndyCar looks like the only option for the 2X world champion, but could we see him only compete in one race? Just the Indy 500?
Let me know below.