Bayern Munich would have been the ideal club for Cristiano Ronaldo but due to his age and how he is playing Bayern Munich dont want him.
He will probobly stay in Man utd whether he likes it or not so he wont play the champions league next season at all
Actually age is not a problem for Bayern Munich Ronaldo is still reliable if he really moves to the Bundesliga, Lewandowski is also old player almost the same as Ronaldo
But the main problem for Bayern Munich is that they cannot afford Ronaldo salary or they think it's too high, currently Manchester United pays Ronaldo 400k Pounds per week not including bonuses.