The widest point I've found looks to be just a shade under half a mile, though even there the swath of significant damage is probably only ~150 yards. It's definitely reminiscent of a few other tornadoes in that photo - also reminds me a lot of this Jarrell photo visually:
There are 10 photos in the series. As far as I know they've never been released or published anywhere, but I can't say for sure. I talked to a family member of the woman who took them rather than the woman herself. They were taken from Selkirk Bush Rd, roughly around the time the tornado was crossing the railroad tracks on the east side of Newton Falls. That area is mostly open fields, so there's no good way to judge its exact width at that point.