At one point, I couldn't skip coffee for a day without getting a full on migraine by mid-afternoon. That alone was worth massively cutting back. I wasn't even drinking that much coffee at the time. Usually a double shot cappuccino in the morning and possibly a cup or two of regular coffee in the early afternoon.

These days I drink a single ~300ml cup of coffee each workday morning, brewed with a 3:1 blend of decaf and regular coffee. I went an entire week over the Christmas holiday without any caffeine and all and had no ill effects.