“The Senate chamber is just way too small.”
While the House chamber is larger, the seating arrangement with minimal tables enables a much larger seating capacity. Take the desks out of the Senate and set up chairs throughout the chamber, it could likely accomodate the House, Senate, Supreme Court, Chiefs of Staff, and Cabinet members, but would be very limited on other guests. However, if Nancy forces the issue, this is where it should go - and likely many Democrat Congress members would opt out of attending leaving seats for more supportive guests. Leave an empty seat for Nancy simply for effect.
Clarification, seating would need to also be in the Senate gallery, which seats a few hundred