Ronaldo has already said he will stay at United even if they fail to qualify for the Champions League. United is more than just another club for him, so I don't think he will change his mind. Given his age, there is a possibility that we will not see Ronaldo in the Champions League anymore, but I agree with his decision. Let him finish his "big" career at United, and in retirement it will be possible to play in America or somewhere else.
It would be better if that was the case because even if he didn't have any talent in the Champions League, he would seem lacking later on, but again he would have realized that his current age was about to reach the end and of course it would be very bad if he continued to change clubs at the end of a different career him now.
MU is a team that carries a good name and it is only fitting that he spends his time at the club that made his name
I think you end Ronaldo career a bit early. In my opinion, he is able to play 2-3 very good seasons more. Of course, it all depends on him, but knowing his love for football, it will not be easy for him to leave the field. Staying at Manchester United is a strategically good decision for him, but in my opinion he should risk changing club at least one more time.
Hey may able to play for another 2-3 seasons but he wont be able to play full time. Age does a matter and he may not be able to adapt with younger players and new strategy effectively. I dont understand why Real Madrid wants him to come back or why Ronaldo want to come back to Madrid.