This from the DM's updated story! They turned it down on Saturday morning then changed their mind!
While every effort had, it is understood, been made to facilitate the Duke’s stay, as a courtesy to staff and others involved, the Royal Household does require a minimum level of notice to ensure he could be hosted appropriately at a Royal residence.
Since this offer was first made, every indication from the Duke and his senior team has remained that the accommodation was deemed unsuitable, including in correspondence received on Saturday morning which formally declined The King’s offer.