Utah's ability to win a conference title rests wholly on the Pac 12 having a down year. If USC and Washington (Petersen) are on top of their game, there is nothing Utah can do. I think USC has the wrong coach, so they will be vulnerable more often than they should be. When they are vulnerable, Utah would have to peak the same year. And then Washington would need to be down as well.
I think 3-5 years is a decent guess for the South title. It could be 100 years before they win the conference. Winning the South every ten years is probably the best Utah can do in the PAC.