Silver linings it seems, finding people to drink with.
However, if they can't cater for your dietary requirements. then you can raise hell as that can be considered as discriminatory, and bad publicity for them would not be a good thing. So perhaps you could use it your advantage by putting forward a lucid arguement on how poorly you think you've been treated and are so expecting some goodwill gesture to be offered by them as means of compensation. Like being bumped up to first class as well as being provided with a personal chef to cater to your needs.