Someone may be interested in trying my substitute. I cannot drink coffee, so I substitute a cup of hot chai tea made very strong.
First, I make an infusion of spices that I keep in the fridge: 2 quarts water boiled with 2 or 3 sticks of cinnamon and 1 Tablespoon each: whole black peppercorn, whole allspice, whole cloves, cardamom seeds, star anise. Boiled until reduced by half, then strained into a quart jar. The whole house smells like heaven while it boils!
I heat up a bit (about 1/4 cup) in the microwave before pouring it into a large cup of strong black tea, add a splash of heavy cream and a couple drops of liquid stevia.
I love coffee of all kinds, but it gives me terrible indigestion. And now I am totally addicted to my morning tea.