I also think of the next reign.
William and Catherine are establishing a forever home for their family.

Clarence House can be the forever home for Charles and Camilla. Whoever goes first, the other can live on comfortably without being forced out of their settled home.

In time, William and Catherine will have to choose between BP and KP as their London residence. I don't see them maintaining both.

To me it makes sense to develop "family" homes and leave BP to be a formal setting. That would avoid forced disruptions to living quarters and forced "eviction" of dowagers.