Unmedicated, I’ll drink approx 10 litres a day. Medicated, I have to be careful, so probably about 1 and a half litres, though I don’t measure. Once meds wear off, and thirst starts, it’s open season. I’ve done about 4 litres this afternoon already and am waiting to take my meds, but am masochistically enjoying the drinking at the moment.
Not a lot as plain water - just enough to get my permanent meds down safely. But quite a lot in cow's milk, oat milk, coffee and tea. More plain water in very hot weather of course.
That article seems a bit wishy-washy (pun intended) wavering between health and economics.