If Bayern Munich's only goal is to win the Champions League next season, they will want to have Ronaldo in the squad. And if they have long-term plans, they will definitely look for a young player to replace Lewandowski. However, if Lewandowski leaves Bayern Munich this season, the Munich management may offer to sign Ronaldo.
Ronaldo is not a guarantee to win the Champions if Bayern Munich signs him into the club, to me I would prefer if Bayern Munich will replace Lewandowski with a good and young player that can last longer in the club. Bringing chrstiano Ronaldo to Bayern Munich it is certain that he will make the team to win the Champions League because of his is age and he will be retiring soon . Bayern Munich can win the Champions League without Ronaldo just as Manchester City.