I was looking for a solution to my situation. Believing that the military had that problem worked out, I posed my question. I like to seek the counsel of someone who is smarter than me. From there I can make the determination as to will it work for me.
There are solid fuels out there that are packable. I have not been able to get a single Esbit cube to bring an 8 ounce cup of water to a boil though. These cubes are smaller than the old "Heat Tabs" and do work well. The test was near sea level in mid 40s (F) temperatures. It took 2 cubes to reach a boil. Boiling is not required for a cup of coffee, especially instant. In the woods, I usually use the Esbit to help start a good wood fire rather than for cooking by itself. It depends on the rules where you are.
I don't need my coffee boiling. I just need it warm.
Jeanette Isabelle