It seems like I've welded a million snap-ties to rebar to make custom-length ties for odd width or hard to brace pours. I've used cat heads and pencil rod or 9 wire plenty of times, too, but never liked those as much as welding ties.
Also, remember that an edge form generally don't really get more more than a certain amount of pressure on it. After about 2 or 3 feet back from the form, it don't matter if the pour is 5' wide or a hundred miles.