No interior shots of the interior of the existing house yet (they're coming, according to the agent), but gee, 23 acres this close to town? That's enticing. There's a survey available showing a possible 5-lot subdivision, with each lot at least 3.5 acres, but I'm not sure there's a market for such a huge, expensive development. The acreage and house are being sold as one parcel, which is understandable, but unless one buyer can afford to, and risk, building four new houses and spend millions to renovate the original house or, possibly, sell some of the lots to other builders, this will probably prove a tough sell as a subdivisble property.
A very wealthy single user could make this into a showcase — are there any of those left in Greenwich, or willing to move here? Check in a couple of years from now to find out.