Your husband has to check into a flight at 5am in the morning and the city he needs to do so in is a 4 hour journey away.
He shared his room number with you and appears to be trying to keep you updated.
Let me add some perspective as an outsider to add an ounce of sanity to this :
I am assuming he's travelling for business. This means they have probably arranged his day for travelling to the city for this flight in a manner which is least disruptive to his working day. This may have been completely out of his control. He could be sitting in room 38 on teams calls.
That could be complete nonsense but again he has to drive four hours and it's completely unfair to expect him to not sleep through the night and get up and drive from midnight / 1 am to get to a city four hours away then go on an international flight.
I think you're being unreasonable. Even if he has a friendship you're not happy with, you need to learn something very valuable - no amount of you exerting control is going to stop someone from cheating. In fact you're probably going to make it more likely to happen if you continue to be a green eyed monster.
Stop calling him. Stop asking him where he is. Stop asking him who he is with. Stop thinking about him. Because if he is cheating you will soon find out and you shouldn't make yourself miserable.
Just relax, pour yourself a glass of wine. Enjoy your time apart and think about ways you can work on your insecurities and your marriage.