This is dependent upon many things, such as condition, size, condition, terrain, and condition. Some animals have superior coordination and structure and seem to take in the terrain and heavier loads better than others. All llamas are not equal. Such animals may be fine for a few miles in easier terrain. You will find everything between the two extremes.
Some llama packers like to cover greater distances.
It varies with each person and each animal. Some commercial packers have loaded 100 pounds on their well-conditioned animals. These are animals that have proven their endurance and have demonstrated their ability and willingness to work. Handlers needs to consider the physical and emotional makeup of the animal, conditioning, weather, and terrain in figuring how far and how much a llama can pack. A key to success is to start slowly with the process.