Can I say Chatsworth House in Derbyshire, England...
Chatsworth house official website
It still had the Duke and Duchess of Devonshire living in it... so it's lived in still. But now it's a business to get money to pay for renovations and the upkeep etc, on the 'Chatsworth Estate' there are a number of properties that the Duke rents out to workers ofthe estate etc etc.
also can I mention Calke Abbey....
it's not a real abbey though!!!!
National Trust | Calke Abbey | A brief history
This was lived in up until about 1985 when the owners, The Harper Family had to donate the house to the National Trust because of the cost to run and keep the house running.
The National trust have keep the house as they found it...... a step back in time!!! and this is how the Haper Family lived in it.. till about the 1980's.
In the US, Hearst Castle is a must to go see.
At the back of my mind it's nice to think that the insperation of RRH house comes from places like the ones above i mention and other palaces across Europe etc.