Pascal - I feel your pain.
My job involves buisness trips away and drink is a massive part of them. You have to get together in the evening or questions are asked.
All I can stay is keep sober, fake it until you make it, when you get the chance to go to bed, do so. Treat yourself in bed with a massive hot chocolate. Enjoy thinking about the morning, when you wake up guilt free that you did not make a fool of yourself in front of work mates.
YOU CAN REALLY DO THIS.
XXXX