I have read that story about the Queen as a little girl as well. Story could be true, but a lot of Royalists biographers, (and I like the British Royal Family,), but many try to paint him as a savior of the Windsors and look away at his character with regards to treating his family. His eldest grandchild, the Earl of Harewood, was known to share some not too flattering experiences with his grandfather, and all five of his sons may be able to trace some of their problems to his "style" of raising or not raising kids. Edward VIII, we know his issues, Albert (George VI has a bad stutter,) the Duke of Gloucester (drinking), The Duke of Kent (drug addictions), and poor Prince John (hidden away because of his epilepsy until he dies with little or no no contact with his family at the age of 13). Again, sorry I digress and like you say, "back to the Romanavs'".
You are right, he did make the offer and withdrew it. As he was never really that close to the Prince of Wales, and he was close to his mother, but she could not make him reverse his reversal, I can see him behaving and making the same decision he made despite a daughter-in-law from Russia. Tatiana or Olga. I still think the Romanavs' could face the same sad results. George V was more concerned with the public perception of himself than he seems for the safety of family members.