I have a huuuge coffee cup that I'm sure it's used at restaurants for sauces and soups. It's about 24 oz or maybe more. I'll have about three or four of those a day, sometimes less, but that's my usual.
Maybe I don't put too much coffee in it Nymore since it always tastes a bit diluted, but it's certainly more than anyone I know.
Weirdly enough, the times I've had symptoms of drinking too much coffee was when I was drinking out of regular cups. 🤷♂️