The video shows the standard way of coiling boat line, or any other line for that matter. Works on thin line & cable up to what can be held in the hand when all coiled up.
Long lengths of 30amp & 50amp shore power, not so much.
After some years struggling with 25' of 50amp I now use a method I used for an en extra long length of spare anchor rode that I had for the boat. Flake it into a laundry basket.
Put the trailer end into the basket first with enough hanging out for the female RV plug to reach the RV shorepower input receptacle. Flake the cable into the basket with the pedestal plug last in ontop.
Now all I have to do is take the basket out, plug into the trailer, pull enough out of the basket to reach the pedestal leaving uneeded cable in basket & shove basket under the trailer out of the weather.
The basket with cable in it is one easy unit to handle.
