We have tons of examples of even greater feats such the Egyptian's moving massive stone blocks many miles. If it were a just a matter of thinking about moving 300 lbs 20 miles the WORK accomplished would represent 31,680,000 ft-lbs of energy. Fortunately dragging something along usually involves less pulling force to overcome friction than the weight of the object being moved. A good set of ball bearings and low rolling resistance tires, as provided by a quality trailer or cart, can push the pulling force down, way down. On the flats if dealing with a realistic Coefficient of friction of 0.02 the pull force would sink to 6 lbs, thus the WORK involved to accomplish the chore would also magnificently decrease to 633,600 ft-lbs.
Work is distance times force.
We modern bipedal apes seem to be fixated on the notion of time. Power is Work per time. The faster Work occurs the greater the amount of Power needed. The slower Work occurs the lower the amount of Power needed. The unit of measure HUP stands for human power, as contrasted cleverly to horsepower.