Here's the thing with that. You could fly that plane on a 1S, but it would take a lot more amperage and your KV would be a lot higher. The difference between flying it on 3S and say 5S is the amount of amperage you have to pull to make it work. Because the higher cell count has more voltage, the amperage draw is less to do the same work. The inverse is true as well. If you lower the voltage, it takes more amperage to do the work.
Since KV is revolutions per minute per volt, a 1000 kv motor at 3S or 11.1 spins 11,100 rpm at full throttle.
That same motor on 4S or 14.8 volts would spin at 14,800 rpm at full throttle.
To prevent over speeding the prop, you need to lower the kv accordingly which is why you always see larger motors have lower and lower kv based on the higher voltages they are supposed to be matched with. This all keeps from running ridiculously huge esc's with massive amp draw, heat, and battery sizes.
Looks like the guy in the video has a successful setup. You could go with that. Personally if it were mine I would stick with a 4S or possibly a 5S setup with a smaller esc. Actually the esc I recommended was a 60 amp because it's oversized for safety. The setup I had called for a 50 amp but it's better to run one a bit larger than required.