I think Ronaldo still does his part well - obviously not as good as 10 years ago - but he could do with some help in terms of service. If he ends up leaving there can't be that many suitors. Wall of text below but in summary I can only imagine him at Manchester United, AC Milan, PSG and Atletico however small the chances are for him joining those sides. Otherwise it's of to MLS, China, Qatar.
Bundesliga - No team will/can have him at the moment.
Ligue 1 - No team will/can have him at the moment.
* Perhaps possible if PSG want to add another Galactico after one of Mbappe/Messi/Neymar departures. Would make sense from a commercial point of view. Could actually make sporting sense as well if Messi + Mbappe leave. Neymar and di Maria feeding Cristiano would make for a success offensively and perhaps even work defensively.
Premier League - Stay with United or leave the league.
Too late now to join City, Liverpool won't have him, Chelsea out of the question.
Serie A - Perhaps AC Milan.
Juventus is a no, Inter are covered up front and usually don't go for players at Ronaldos stage. AC Milan on the other hand have some pedigree when it comes to craming out the last juice out of 30+ players. Ibrahimovic might retire/go back home to Sweden/China or whatever, Giroud is 34 himself and although playing well is not a star name like Ronaldo. Through the years we've seen Ronaldinho, Beckham, the aforementioned Zlatan, Rivaldo etc. join while 30+. Pirlo, Seedorf, Maldini and many more played well past 30 here.
La Liga - No team will/can have him at the moment.
He won't go to Real or Barca. Atletico would be fun, I bet Simeone could use him very well for a couple of years. But they likely can't pay his salary and Ronaldo probably don't want to ruin his Real legacy.
MLS - Every team would want him.
Ronaldo can pick and choose if he wants to live in Miami, Los Angeles or New York.
China - Every team would want him.
Ronaldo can pick and choose if he wants to live in Beijing, Shanghai or Guangzhou.
Qatar/Saudi - Every team would want him.
Ronaldo can pick and choose team and location.