When I'm working from home I drink about 4 cups a day, usually no later than 3:00 PM but occasionally I'll have a 5th cup as late as 5:00 or 6:00 if I end up working late. Some days I switch to tea after 3 cups, sometimes caffeinated tea, sometimes herbal. When I'm on travel I don't have a much desk work, so, it's usually 2-3 cups a day, and every once in a while a cappucino or a latte after dinner.

One place I worked at had a cafeteria with a self-service espresso machine that would grind the beans and give you latte, cappucino, mocha, straight up espresso, or Americano. And it was free. I had to set some limits on myself there.