Good point. Cruz does not want to surge to rapidly, because then his poll numbers will be harder to maintain, and then if they fall even a bit, stories will come about him peaking and so on. This has happened somewhat to Trump recently.
Cruz surging in January right before the Feb 1 Iowa caucus sounds great to me!
It's happened to Walker, Fiorina, and to an extent Rand Paul and Huckabee. It's no use peaking in August, September, October, November or even December. Start really peaking in January for Iowa and carry the momentum to the SEC primaries and beyond. This is a marathon, and like most marathons, the lead changes quite a few times before the final stretch. Lots of runners rush to the lead at the start of the race and run out of steam by the middle of the race.