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
Although Man United always gave CR7 a great position, it is well known that he has a great fan base there, and he realized that while he was playing at Real Madrid they were waiting for him at United, it is known by simple inspection that any player who makes him feel at home will give his all, regardless of CR7's age, because all the studies he has produced according to his physical condition are almost the best, in fact he has the equivalent in terms of his physical sports condition to a 27-year-old player, so with the attitude and preparation of CR7 he will contribute all of him to United, and after the World Cup it will be another attitude depending on how Portugal does, but I am sure it will be a very positive attitude.