I also work in Finance as does my sister and many of my friends. My father still works on the money markets. My godparents and parent's friend were also in the industry and I've been around enough couples bickering to realise that there is a way forward - communication, trust and ground rules, rather than ending the r'ship. Id advise the OP to agree nights that the oh can socialise for work (My Dad would do Tues and Thurs, and alter his days if a big client was in, but would try yo cut back the following week), make clear the sleeping arrangements, introduce a date night / lie in and ensure that they know when the oh would be in, and that a text would be sent if plans change.
Also to people who aren't familiar with the sector, I dont think you can claim that someone who goes out is an alcoholic. When it comes to client entertainment it is an integral part of the job. You can't 'not' do it just because your wife said so. In my company we are not allowed to trade if we have had more than two alcoholic drinks, so given that, it's not uncommon, on occasions for my colleagues to not return to the office. Obviously you don't have to drink but in a pressurised environment (and peer pressure from colleagues) it's not surprising that the OP's partner does. BTW - I'm not saying that the partner hasn't behaved badly, just that the situation isn't as black and white as he prefers drink to the baby. By socialising he could justify that he is protecting his job and providing for his baby.
Good luck OP. My parents have been married 37yrs now. It is possible to go forward if you're both committed to making it work and working together. xx