People tend to check in during these times:
Lovely cafe in Kenwood House. Great ambience, excellent coffee and cake. Check out the Old Kitchen room too, beautifully maintained.
The food is okay, nothing special.
If you have a dog and the Steward's Room is closed, go in the side entrance and tie your dog to the green stair railings, so you can see the dog through the window.
Sit outside :)
A lovely place to chill after a long walk
Hot weather? Try out their icecream
Breakfast is very tasty & quite good value!