Anonymous wrote:L’Auberge Chez Francois:
https://www.laubergechezfrancois.com/
I second this. If you are feeling more casual, they have a brasserie on the same property that shares the kitchen -- Jacques Brasserie.
I agree with PP that suggested The Inn at Little Washington as perfect for a milestone anniversary, but it would be almost impossible to get a reservation there at this short notice.