I used to drink that amount, with the addition of 2 spoons of sugar (12 grams) added to each cup of coffee. Since I drink lattés, you also need to add the 6 grams of lactose, and the 4 grams of fat. About three years ago I already switched to 0% fat milk, and since three months I add lactase to my milk so all the lactose is converted to glucose and galactose, which makes the milk sweeter, but not higher in calories. I also add some artificial sweetener, but since this does not produce the right kind of sweetness, I still add 1/2 teaspoon (3 grams) of plain sugar. Together with other measures, such as freezing my lunch meats and cheese to avoid snacking, I have lost 8kg since last July.
I was also reducing the number of cups per day, but then the covid crisis started, I was forced into mandatory vacation and gained 3kg again.
ETA: speaking of mandatory vacations: I have been drinking wine and eating Mediterranean snacks in vacation-sized amounts lately, and apart from the weight gain, I also start to feel worse physically again. I have a sort of love/hate relationship with alcohol and drugs: I like to use it a bit, but when taken in too large quantities (which is still a lot less than lots of other people) over an extended period (usually a matter of days), these start working against me. This is probably why I never became an alcoholic or drug addict.
“I have never tried that before, so I think I should definitely be able to do that.” --- Pippi Longstocking