It's better for him still stay at manchester united. Leaving MU to the another club didn't mean if he can get a better club. So many big clubs have been rejecting him. He must learn a lesson from there. As long as he will be actively playing for MU and why not? it's better rather than try to be a subtitution only for the another club. He also tried to bring MU to the champion league next season.
Ronaldo should remain in Manchester United regardless of their absence in the UEFA Champions league. He is no longer in the top class like he used to be and he is getting old. He needs a club like Manchester United where he would be respected and given the right treatment he deserves. He should not forget the hostile treatment he received from Juventus when the club failed to make it to the Champions league finals. With a new coach and their new signings Man U might make it to the Champions league next season.