I absolutely agree with you.
Many blues didn't want Peter Schmeichel before he signed but i did because I rated him a world class keeper with a professional attitude, even at 38 when he signed for us. In the two derbies he played in we drew at OT and won at home. He was punching the air in delight at beating his former club, that's the professional attitude and winning mentality he had!
Also many blues didn't want Tevez either but look how well he did for us before his shenanigans with Mancini in Germany.
Ronaldo is still world class and a great winger/striker. Still fit and energetic with pace that belie his age, plus his injury record is exceptionally good. I've been reading up on it and he was was out injured for 59 days in 2016/17 season due to a collateral ligament injury. Since then he's been mostly fit apart from a few minor niggles.
If we forgive and forget Ronaldo's ex United connection like we did with Schmeichel and Tevez then signing him as a short term solution is a no brainer. Sign him up i say.