You do realize that the last two winners of the Iowa caucus were Huckabee and Santorum, right? Yeh, they went far.
IMO, the caucus winner in Iowa does NOT determine who is getting the nomination.
This is not a typical election. Cruz is done if he does not win Iowa. He has put every one of his eggs in that basket. Trump does not need Iowa but will likely take it, as well as the rest of the states which are all lined up for him now. If Rubio can finish second in Iowa, it’s over faster for Cruz.