We didn't actually visit this place for the museum, café or any other features, but attended a wedding of a couple who my wife knows.
The venue was well run with great space for the guests. The newly weds had a quartet band playing to lead them in in the upstairs hall which was lovely (though maybe not a feature of the museum!)
The food was great, though the main course of steak was a mixture of rare steak to rare-medium which isn't everybodies liking. The waiting staff were very helpful and generally very pleasant. The guests had a marquee set up for us to go to after the dinner which was testament to how well they looked after the house - drunken guests in a beautiful place as this would probably not be a great idea! There were also plenty of lovely views of and from the house as well as the well kept gardens.
If there was ever a wedding that we were invited to again at this house, we would be very excited to return. We just wouldn't order the steak!
If you own or manage Sledmere House, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.