George V "gifted" the Royal Lodge to George VI when he was the Duke of York and not expected to ascend the throne. I get that sensibilities have changed and maybe to some it is not a good look that royals live in vast properties that are part of the crown estate. But at the same time these deals were made when sensibilities were different and IMO I am fine with allowing the deals that were made stand and then make different choices for future dispositions.
Charles very well could be eyeing the Royal Lodge for Camilla but that makes no sense to me. If the Royal Lodge is too much house and property for Andrew and Sarah, as some have asserted, then it is certainly too much house for Camilla. In the case of Andrew and Sarah, they have lived there for years, raised their children there, and while their daughters have left the nest, it seems like they still spend time their with their spouses and children. Don't get me wrong, if circumstances necessitate that Andrew and Sarah leave the Royal Lodge and his daughters and their families experience grief and disappointment, that is a champagne problem, but the Yorks are the royals with the closest ties to the property.
If Camilla outlives Charles, she would probably still remain in Clarence House and Birkhall will probably be at her disposal, and perhaps even something on the Sandringham estate. She has her own home Ray Mill. To my knowledge Charles and Camilla have no strong affinity to Windsor, I can see Windsor being attractive because of its proximity to London, so having a property where someone can escape London but still be convenient to London is appealing. If that is desired for Camilla, then an apartment in the castle should suffice or Frogmore Cottage. Also the aforementioned change in sensibilities would apply to Camilla too, and if I am correct in my speculation about what properties widowed Camilla may have at her disposal, she may not be that far off from what QEQM had at her disposal, and QEQM was known having a high standard of living that was more akin to the 19th / early 20th century Edwardian era, rather than the more pared back late 20th century.