Your dh sounds a bit like mine, M44. When the dc were little, we lived in Essex and he commuted to London, and worked long hours, and was often much later home than he said he would be. I hated it at the time, more because of the unpredictability of it, and how difficult that made it to plan things like meals, than because I resented doing the childcare etc.
If I knew he was going to be late home, then I knew I'd be doing bedtime on my own, and that was OK - but if he'd said he'd be home and do bedtime, then I'd subconsciously be looking forward to the help, so if he didn't turn up, it was a let-down. Plus I had to deal with sad boys asking when daddy was going to be home.
It also made meal planning difficult, and he liked me to eat with him (and I liked it too) so I ended up cooking one meal for the dses and one for us later on - sometimes very late. As I got better organised, I did try to make meals that we could all eat, but that could be dished up at different times - ie two shepherds pies, or bolognese/chilli etc, which made life easier.
He did come home drunk sometimes, too - not regularly or often, which would have been a show-stopper for me, but occasionally - and I really hated that, so I can understand how cross and upset you were when your dh did this last night.
One thing that worries me a little is the fact that he got so drunk whilst doing corporate entertaining - is that normal for the company (ie do lots of people get pissed at corporate events) or might there be managerial disapproval of him getting drunk? It might be worth asking him. Dh's work was completely dry, so he only ever got pissed if he went for a drink after work with colleagues, so I don't know what the corporate culture on this is.
I wouldn't join the 'pack his bags, kick him out' people, unless this is regular and frequent behaviour (the drunkenness). However, it would be perfectly reasonable for you to talk to him about a few ground-rules - particularly that he phones or texts you if he is coming home late, so that you can plan your evening - and you could say that you would obviously do the same, if you were out and he were at home with the dc.
My dses did see dh drunk (very occasionally, and no longer, as he has given up alchohol altogether for the past 5 years), and I don't think it did them any harm - on the contrary, I think it showed them how stupid you look when pissed. Obviously, I wouldn't be saying this if he had been an aggressive drunk or abusive.
I would say that, in my experience, things do improve. Now dh's hours are much better (plus his commute is much shorter) - but ironically, as the boys are teenagers now, childcare is much easier too, so I don't need the help as much as I did when they were little. I suspect that this is often the case, because early on in someone's career they need and want to appear keen and willing, and so end up staying late more often, whereas later on, you can bring more work home, and also you have more people who you can pass work on to (young eager people) so you can come home.