Turning Check in and out dates into number of rooms per night for rooming lists

Hello! Hoping you can help me - I'm a meeting planner and have to send hotels rooming lists with the number of days stayed for each night. These lists can be hundreds of people long which can be a pain. I have names and check in and out dates and have to send the hotels that information, and then have to figure out the total number of rooms per night for all the people.

I've attached a simple spreadsheet here to show you what I'm talking about. Right now, I just go in and put "1" for each night, then add up the columns.
Do any of you sage folks have an easier way for me to do this? Believe it or not, I've been doing it this way for years and of course screw it up each time I have a lot of people staying at a hotel!

Thanks so much!
Kim