I believe 150W allows only 1.3 AMPS . That's not much for any device that is generating heat. Its plenty for many other applications but once you want heat , you need lots of Amps.
I would think you can just see the amp draw of the coffee maker on the label or molded into the base and then just just multiply the amps by 110 to get a very close feel for the wattage of the inverter you need.
Now many of these things will deliver even 100% over their rating but only for a short time. A very short time.
I like the blender idea and had one on my boat for many years. For coffee , carry a small single burner stove , I always used a Peek1 and it was great and lasted 30 years. Alchohol evaporates lighter than air if spilled or leaked so is a fairly safe fuel....unless you drink it!!
