I interpret this advice to mean that if you think 20 feet should do it, get a 30 or 50 foot cord. Personally, I prefer having more than one. At home I keep a p

I interpret this advice to mean that if you think 20 feet should do it, get a 30 or 50 foot cord. Personally, I prefer having more than one. At home I keep a pair of 50 foot cords of the same gauge as a 100 foot should be made of. I usually only need one, but sometimes need to chain both.