I tried to circular knit a scarf without a pattern a few years ago, and when I bound off, the scarf was 20 feet long.
Andy and I laughed until we cried, and he dubbed it the Shaq Scarf.
Instead of wearing it, we use it as garland for Christmas decorating.
I fear a 20 foot scarf would be slightly dangerous to wear. Especially if you are clumsy like me.