You might get away w/it, and it's worth checking one out in person if there's a nearby shop with one in stock.

I looked at the geo for the FX 3 Disk, and the effective top tube is only 7 mm longer on the XXL than on the XL. You can make that up with a stem swap if it even matters. You might notice the bars come out higher relative the height of your seat when riding the larger framed bike. That's the main thing I notice when I ride my son's Kona Dew, which is a couple of sizes higher than I would normally fit.