Actually no. This is directly from the Seattle Times article on the folding wingstips. They were originally offered on the 777-200, and were 21 feet long.
The 777-x proposed folding wingtip is only 10 feet long.
"In fact, it isn't a new idea. In 1995, Boeing obtained a patent for a folding wingtip design on the original 777, which had a 200-foot wingspan.
That mechanism was even built and tested — the full-scale model used then is on display at the Museum of Flight Restoration Center at Paine Field in Everett. But no airline ever bought this option."