We’ve long known that politics in the U.K. & US wouldn’t be believable as fiction, even in The Thick Of It or Veep

Trumps team booked the wrong Four Seasons, not the Hotel.
Here is Rudy Giuliani announcing Trump’s legal action in the Four Seasons Landscaping company car park

The Four Seasons Hotel distanced themselves from Four Seasons Landscaping
The Adult Bookstore selling dildos next door to Four Seasons Landscaping & the Crematorium across the road couldn’t be reached for comment

So it seems the timeline is:
1 Trump tweets that the press conference is at Four Seasons Hotel at 11 w/o checking with hotel
2 Staff find Hotel won’t take it
3 Staff find another Four Seasons - the gardening company next to a dildo shop & crematorium - 30 mins further away

4 Trump sends another Tweet & moves time to 1130 to accommodate additional travelling time
5 Staff get there & find no room big enough so use car park in a space between a fire hydrant & a hose
6. Biden win announced whilst Guiliani is talking & Press walk out after telling him