Cowboy coffee left it chewier than we liked, even with the trick of a dash of cold water to settle the grounds.
A french press worked ok, but was slow and took a lot of water to clean up. That's a concern when you're mostly boondocking in the desert or mountains without a handy tap to get water from.
Coffee bags and instant/ freeze dried didn't have the taste we wanted. (putting it politely).
I tried running a small coffee maker off the solar batteries, but the power used was more than I have available. especially with multiple pots.
Next we tried a collapsible drip basket that sat on top of the coffee mug. It got closer, the taste was good, but took a long time to dribble the water in so it didn't overflow, and also got cold pretty quick from being exposed while dinking around with it. Also... we had to clean up more than once when the basket got knocked off the mug.
Remembering when I was a kid, the waitresses at the diner used to prepare a basket of grounds, and then dump a pot of hot water into the top of the coffee maker and walk away while it trickled into the grounds gave me a target.
Here's what I came up with,
First, you have the whole shebang in an insulated carry bag that Kat made for me.

Here's the parts laid out. A thermos, the collapsible filter holder, a water pot, and a stand to support the whole thing.

The first step is to screw the legs into the lower ring and set it over the thermos.

Next the filter holder sets into the hole in the lower plate.

The uprights plug in to hold the upper ring in position.

Add the filter and grounds. Clothespins keep the filter from folding over.

Another shot of this stage.

Next, heat the water, I put the water pot on to preheat it while the water heats.

Once the water boils, set the water pot in place.

Here's a closeup of the drip hole in the water pot. You want it to drip fast enough so the water/ coffee stays hot, but don't want it to overflow the filter basket.

We add an inverted bowl to the top of the water pot after filling it with boiling water. This keeps the cover out of the water.

Finally, cover the whole thing with the carry bag. Now it's clear why it is insulated, it keeps everything hot while brewing.

Now, you can go ahead and make breakfast, or whatever. The coffee brews, then drops into the thermos. It will stay hot and ready to drink for a long time while you are busy otherwise.
A few notes on development. I found the stainless pot at a garage sale. I'm looking for another similar one since I want to make another one of these for our other trailer,
The legs now screw into the lower ring. The first proto I made had then plugging in like the upper ring support posts... stood ok, but when you tried to move it, one leg always fell off. Threading them in solved that problem.
The hole in the water pot started out at 1/16". After a few tries, I opened it up to 5/64". this proved to be perfect. Water runs thru fast, but doesn't overflow the filter basket.
I made the support rings on my 3D printer, but carefully cutting them out of plywood would work just as well.
Bottoms up!!
Sam
(BTW, we call this the alien coffeemaker because it reminded us of the alien machines in "The War of the Worlds")