"You're guaranteed to love this" sounds like hyperbole, but was entirely true for us. Agri and Roger were welcoming and attentive without hovering, and the breakfast was lavish and varied. Our bedroom lived up to the lovely photos, and the back garden give an impression of being in the country rather than north central London. Our bed was deeply comfortable. It's as close as an affordable London b&b can come to the experience of being a guest at an English country manor.
The tube station is near enough to be easy for folks with luggage to drag, and we recommend the Nahling Thai restaurant ten minutes walk from Blenheim house.
Agri and Roger, thanks again!