Room 239 is most likely in the US Capitol since congressmen could not leave all day today.
The Eisenhower Executive Office Building where Pence has offices is a pretty long way from the US Capitol, having a hard time seeing why they would leave the capitol if votes and deliberations were occurring all day. Plus there is a Room 239 in the Capitol bldg. Doubt that any of the minority members were present at the meeting so that leaves 13 Majority + who? A good place to start are the people who are no on the HPSCI Majority yet were still aware of the contents of the memo last night.
True Pundit reports they were using Signal to communicate = big mistake. Ever since Snowden recommended people use Signal NSA focused on compromising the app and was apparently successful.
JB = FBi Chief Legal Counsel James Baker