Next, we can throw up a nice fence around the monuments, national mall, congress, white house and Smithsonian Museums, declare it a national park and charge a nominal admission for guides, security and concessions.
Congress would have a big screen for a Zoom type meeting when it is in session and well as all the committee hearing rooms. They would be invited to fly into Washington a couple of times a year for maybe an opening and closing session but spend the rest of the time in their home state or district office on an internet connection.
No center of power and no sinecures. Washington, DC would have to reinvent itself as a town catering to tourists, history and museum buffs. The remainder of the district would be retroceded to Maryland and repeal the 23rd amendment.