Normally I will have 3 Glasses of Champagne in the Lounge and 2 Beers and occasionally a Gin but really depends on time mainly.
If I'm flying CE I'll normally have 1 champagne and 1 beer plus lots of water and tea.
On Long Haul I'm very conscious that waking up with a hangover isn't fun but sometimes I can have 7/8 alcoholic drinks on an 8-10 hour flight!