Perhaps an odd thing to ask, but what are you packing in your backpack for coffee? That sounds lovely, but between the need for hot water, the subpar quality of most powdered coffees, etc, it has seemed out of reach.
For day trips I brew coffee at home and carry it in a vacuum insulated bottle. The bottle smells like coffee even after cleaning, so I have one that I always use for the task.
For multi-day trips I already have a small camping stove (MSR PocketRocket or an alcohol stove), and I pack instant coffee. I heavily prioritize saving weight on longer trips, so I generally drink my coffee out of the same light plastic bowl that I just ate oatmeal out of, which doubles as a decent way to clean the bowl.
For wilderness backpacking I'm a big fan of Jet Boil and their clones. You can make your own freeze dried / just add water meals pretty easily, only using it to boil water for that and drinks. They make a french press insert that actually works ok. Personally I just converted over to earl grey tea. It's crazy convenient to just do one boil for food, one for coffee / tea, and nothing to clean or pack out but a zip lock bag.
For urban backpacking the more high end thermoses are really effective at keeping stuff hot once you've made it.
Not the OP but I take every opportunity to brag about my Zojirushi SM-KHE insulated mug. I use mine every day -- cold coffee and tea are a thing of the past.
I have several friends that really like their Fellow Carter Everywhere mugs if you want an alternative.
+1 for the Zojiroshi. I've owned a variety of vacuum flasks and it's by far the best. Years later and my tea is still scalding hot ten hours later (I usually let it cool a bit after steeping before I put it in because it protects too well). It's gone on dozens of flights and journeys with me and other than a few scratches looks and feels as good as the day I got it. It's also trivial to disassemble and clean.
For multi-day trips I already have a small camping stove (MSR PocketRocket or an alcohol stove), and I pack instant coffee. I heavily prioritize saving weight on longer trips, so I generally drink my coffee out of the same light plastic bowl that I just ate oatmeal out of, which doubles as a decent way to clean the bowl.