It seems Trump and his team failed to book hotels for his trip....
President apparently couldn't get a hotel room for G20
This sounds about right. A friend of mind used to work in the travel department of the White House under Obama; Her department handled trips like this which is a rather large under taking. When Trump won the election they expected their replacements to visit them for training. They were let go on Trump's first day, but no one was ever trained to replace them.