A great inaugural speech could make a huge difference. Anything divisive or gloating could cause long-term resentments. Traditionally, the president-elect and and his family arrive at the White House on the morning on Jan. 20 and have coffee with the departing president and his family. They move in later that day, after the swearing-in ceremony. The hotel rooms will probably still fill up, and the restaurants should do well.
Most plans are on hold.
That's so much for letting everybody know about it. It's always been tough if you're not Mr. or Ms. Big Bucks. The inaugural committees always talk about being open to the public, but there's usually not too many ball tickets floating around. In this case, I suspect the early birds will get those leftover worms. Not that I know of.