Did we mention St Louis Union Station? Still used by commuter trains but not by Amtrak. Its a large place, part hotel, part mall and they certainly have the room but Amtrak likes their Amshacks.
St. Louis Union Station is not really used by any trains at all, except occasionally by PVs parked on one of the two remaining tracks.
The St. Louis LRT Union Station is a good walk from the Union Station Hotel to an area that is just outside the edge of the old station canopy, near where the old signal bridge used to be. The old waiting room is now the Union Station hotel's lobby. While the Hard Rock Cafe and the Landry's are still in business, the rest of the Mall development there seems to have collapsed.
There is lot of construction going on to repurpose the property into a Convention Center or something like that. Most of the old Mall area is now sealed off for construction. Unless you have a hotel key to enter through one of its back doors, you have to walk along sidewalks outside the station property to get from the LRT Union Station to the hotel lobby (the old headhouse).
We were there just a couple of weeks back during the OTOL Missouri Texas Rail Fest and most of us stayed at the Hilto Curio Collection St. Louis Union Station Hotel in the active construction zone.