Iowa gives the winner some momentum - what they make of that momentum is up to them. It does seem that Iowa goes for the candidate that invokes religion the most, so obviously, that is not a good bellwether as to who will eventually win.
Good to see Trump fighting so hard for it though and good to see Cruz fighting back. This is why they call it a race.
Based on what I wrote, a wise person could say the GOP should entirely change the system, move away from Iowa first etc.
And the track record for New Hampshire as an indicator is not much better.
Why? Well the GOP has lost the popular national vote 5 of the last 6 times, for openers. Those results would indicate there is nothing to lose, by change.
Why not start in a two large GOP states, first one conservative and then the next more moderate? Nothing to lose (but money it would take).