I'm sure most would do it. I'm glad you're telling them they should up for 3 f... in a row.
Around what time is the 2nd time: 2, 4 AM? Midnight (after a recovery meal) like @BuffaloKyle says makes sense but not after falling asleep.
What time do you wake them up if they have their own room?
Yes, but they can also earn the same amount having 2, 3 or 4 clients in a day. I know a local escort who goes to Richmond every month to see a client for 2 hours in the evening and 2 hours the next morning, same amount as an overnight but he gets to sleep by himself and have some "me time".