Prince Khalid has kept a low profile in Washington, preferring to host visitors at his palatial compound overlooking the Potomac River in McLean, Va., where he lives with his wife and two young children.
https://www.nytimes.com/2017/09/12/us/politics/saudi-trump-ambassador.html
The gated compound on Orris Street is owned by the Kingdom of Saudi Arabia’s Armed Forces Office, according to real estate records.
https://wtop.com/news/2013/05/two-removed-from-saudi-diplomatic-mansion-in-mclean-after-human-trafficking-accusations/
US, Prince Bandar bin Sultan
He's no longer there. Who is now? But the point is the Saudis have always had a presence in McLean since the late 70's
http://virtualglobetrotting.com/map/saudi-ambassadors-residence/view/google/
Just some more ideas. Thanks for the great digging you are doing.