I think you can just go the home, but it is closed until spring. If you go now, you can walk around the outside and see almost nothing. The center is open which is in town. There is parking in a garage at the end of the street but will look like you shouldn't park there. They will validate your parking in the visitors center.
Not sure but it is part of a tour that you do, you can't just go to the home.
Check their web site
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