Reposting for eyes.
I checked notables and didn't see this but I am pretty sure the "Island" Q is talking about is Manhattan.
I am still looking to see if the county (tax assessor) has floor plans. The pic attached is a building that sold on the same street. Gives you an idea of the stair cases.
I keep thinking that it's too box like to be excavated like that. I am sure the island has tunnels but the 4x4 security cam footage resembles more of a Manhattan townhouse.
There was talk that this was previously a school so still searching for images. The walls do look like they have wallpaper and other "home like" decorations.
HRC, Bill Mahr, sure a ton of others were in NYC at the time. Tweets confirm HRC went to Manhattan Zoo.
9 East 71st Street