You won't win any quality awards but it's possible.
Even running in 720p the overall resolution (3840x720) is comparable to 2560x1080 (UW FHD)
The 570 is capable of running most games at Medium-High settings at 1080p (2MP), however running 3 side-by-side at just 720p (2.76MP), you're looking at very low-low quality to hold 60fps. Trying it at 1080p will make most games unplayable.