Quite so. I think it unlikely Marlborough House will ever again be occupied by the royal family. It's vastly larger than Clarence House, and after Queen Mary's death, it was deemed too costly to maintain for use by the Queen Mother.
I'm a bit surprised to read that Princess Margaret's former apartment 1A at Kensington Paace is being considered. The royal household had previously suggested their intent to phase out KP as an occupied royal residence after the current occupants depart. On the other hand, those current residents (Glouchesters, Kents) won't likely leave for a decade or two, so the KP security cordon has to be kept at least that long. I suppose that coincides with the period that the Cambridges would likely live there - until the present reign ends and they take over Clarence House. Perhaps that's the timeframe the household is considering hanging on to KP.
