Ronaldo would also be wise not to play for another Italian club than Juventus. I think that many fans and enthusiasts like to be seen as an asset there, but it will be different for many supporters. Of course he has the clubs to pick out. Man City was not an option due to the rivalry with Man United. Maybe try another country, Bayern Munich is not a bad alternative and high level too. Or eventually back to Real Madrid? He has won many prizes with Real Madrid and was very important for the team.
I don't know from where you got this information that CR7 will move out from ManU? That was speculated weeks ago but the situation was calm these days since it was unofficially said that he will remain in United and even his teammates announced that.
Of course everything could change at the last minute but he won't join Real Madrid since I doubt they will accept him back for several reasons like his age, wage, the way he left the club, his actual performance... Bayern already got Mane so it is unlikely to grab an old player while keeping Lewandowski with them.