Exdp was a functioning alcoholic similar to what you describe. I ignored it, made allowances for it, minimised it etc for years. I hardly drink and when I got bottles of wine and champagne as gifts for my birthday I would hide them inside my knee high boots so he wouldn't drink them. He found a litre bottle of chambord I'd hidden and drank it within an hour - no one can enjoy downing that much sweet liquer, that's purely about getting alcohol into your system.
He would sit in the computer room every evening drinking and playing games, I felt like a single person but had all the hassle of working and sorting out everything for both of us, to do with the house, washing, you name it. I 'joked' that alcohol was the 'other woman' in our relationship as it took his time and attention off me.
My lightbulb moment was realising that actually I was the 'other woman' in his relationship with alcohol - he loved it and needed it in his life more than me. It would always come first. I had to either accept that or end it. I chose to end it. It was hard as I still loved him but I couldnt live like that for the rest of my life and he was not prepared to change.
I didnt have kids with him, luckily, so it was more straightforward, but please be warned that the 'nice, loving, cuddly' drinker can very quickly become Mr Very Nasty indeed when its clear the relationship is over.