Hi- Here's what we do to have hot water handy for hand washing OR hot beverages without firing up the
propane for hot water (helps with condensation and conserves propane): We use a thermos air pot. I say hand washing OR hot beverage water because, depending on need, the air pot keeps boiled water dangerously hot for 12 hours, or at least mine does for about 24 hours. I can cool that down by adding room temperature water if I just want nice and warm hand washing water and tend to do that after morning coffee is through. It's just nice to have warm water for washing needs.
If you use a gas lined air pot you more than likely will need to be extra careful with transport and use. I use a wrapper I made out of bubble wrap covered in fabric and a drawstring opening for the glass lined one. We also have a steel lined one (three times the cost) which doesn't need to be babied but it stays on the boat because we encounter more thumping situations what with rough seas, etc. If you don't already have an airpot, I would go for a top quality steel lined one. Ours is Nissan and has performed flawlessly for a decade. Our glass lined is a vintage Peacock and it is a tremendous performer but will be replaced by steel lined once it goes. Happy camping!