To be honest, I don't like any of these "examples" at all because they attempt to map "intuitive" concepts, which are things like "size", "more than" and "fewer than" when applied to something that is finite, to something where that intuition doesn't even make sense in the infinite realm.

I mean, in your example, how can the first "infinite bus" ever empty in the first place to fill up the infinite hotel? After all, if it's an infinite bus, people will always keep streaming out of it. When you ask the guests to move from door x to 2x, that request never finishes, so you never are able to stop and then ask for guests from the other infinite bus to access the odd rooms.

What actually helped me understand the concept of the cardinality of infinite sets is to get rid of the whole notions of "size", "more than", "fewer than", etc. and instead just stick to the concept of mapping: is there a single, deterministic function that can output a unique value Y, where Y exists in some particular set, for every input value X, where X comes from another set.

Honestly, I think trying to use the same words like "size of" when talking about infinite sets was a mistake.