The problem becomes even more interesting when you throw in air travel, which means you will purchase your fuel where you begin your excursion. For one thing, you may carry a stove that burns the fuel available at your destination, not necessarily your first preference. Secondly, you may buy a fuel module that has far more fuel than you need for basic cooking. This often means you can boil water with great abandon and leave the filter, etc. behind. This can actually result in a net savings in weight.

Just cross your fingers and hope the shelves aren't bare when you trot up to buy fuel.