These are not the behaviors of the single-digit multi-millionaires I know: "11,000 SF home, own a houseboat, every toy you can imagine, travel the world". They are as you describe. They made their millions in pretty ordinary ways. They worked. They saved. Their houses are ordinary and paid off. Their cars are 10 years old. They are stingy and that's exactly why they are multi-millionaires.
I know a centi-millionaire and a billionaire. Those to are not stingy. And do have all the things you described.