hi tacomas - welcome
well, I was very good at hiding my drinking and not letting it bleed into the other areas of my life...until I wasn't...and that happened very suddenly.
It may happen that way for him, it may not...but the odds aren't good that 'functional alcoholism' (in itself a ridiculous term) lasts long.
The fact is no matter how 'functional' your husband might appear, its already a problem for you...faced with a choice between genuinely responding to your concerns and drinking, he's essentially choosing to continue to drink, so you have a right to be concerned and I agree you have every right to take a hard look.
You'll find a lot of support here
D