Keep educating yourself on problem drinking OP - don’t worry at this moment about trying to control or cure him. You have been doing that for years to no avail. Al anon will help and guide you and PP have pointed to other resources as well.
You will eventually be shocked to see your own role in enabling and supporting his habit - not consciously obviously but subtly - why do you go on all inclusive holidays? why do you do the driving after 2pm? How else are your daily/weekly routines adapted to absorb his drinking?
You think he doesn’t appear pissed but this is a boiling the frog situation - you are just used to his quiet drunk ways. Others including his children see, experience and can call out slow, withdrawn, unmotivated and unconnected parent. You say this is how his own DF was - so maybe it is not the drink. This is just YOUR denial talking.
Your children have had a substandard childhood - that’s not good enough - they deserve better.
You are also complicit in excusing him and minimising his habit. You started the thread saying he is set in a routine and drinks 8 cans on a Fri and Sat only and can stop anytime because he always does dry Jan. But it appears he didn’t do dry Jan this year, the small cans are now pints, the Sat and Sun can expand to Thurs, Sun and Mon and he is up to 32 cans.
The 2pm becomes 11am If he has been out the night before, he starts at breakfast on holiday and will drink for 14 days straight through - this also happens at Christmas - and no doubt at bank holidays.
You have repeatedly said doesn’t touch spirits in the house as if that deserves a round of applause. Issues are related to the number of alcohol units metabolised - doesn’t matter if they come from moonshine or alco-pops.