Hmmmmmm I still would be very surprised if they’re readying it for Harry. He has to quarantine for 2 weeks, correct? And then quarantine from Meghan and Archie (assuming they are not traveling with him) for two weeks when he gets back, not to mention the time he would be in the UK. Could they be preparing it for another member of the family to move in?
I think Frogmore Cottage is the UK base for the Sussexes and will be for their use "forever" acdc1.
There was a discussion a few days ago between Richard Kay, Rebecca English and Robert Lacey in which Ms English said that the original idea had been for Prince Harry to return to the UK once a month for his patronages and charities.
It was almost a de facto way of doing the "half in/half out" that the couple originally proposed.
(Covid stopping it, of course.)
Perhaps part of the prep work for the Duke's visit is to have whatever staff/security he will need, do their own self-isolation before he arrives in a few weeks - so he is not at risk for Covid from them.
I don't think the Duchess and little Archie will be with him. I think he will do his self-isolation and then have meetings, discussions, talks, sign papers to bow out of this and that, and then return to his Montecito home for Christmas.
I think this is either a circuit-breaker, or a visit for some formalities he is still tied to.
Certainly there are "sources" saying the original plan - after the half and half idea was quashed - that say the couple will now "retire" at the end of the review year.
And yes Prinsara, could be why a visit back is needed now.