To keep weight and space down to an absolute minimum, why not take this Lifeventure Titanium Mug with you. Made from ultra lightweight food grade titanium, this is strong as steel but almost half the weight, and even the handles fold down for storage. Essential kit for a hot cuppa on the hillside.
Use as a simple, lightweight mug or cook and boil water directly in the mug. Even use it over a wood burning stove when wild camping.