I agree those polls show Trump ahead but those same poll showed him ahead for two weeks before Iowa. I think the polls are going to be off in NH, SC, and NV now the question becomes by how much are they off. If they are off as much as they were in Iowa, because Trump had 30 in most polls heading in and ended up with 24% a drop of six points. In NH that six points has to go somewhere, my guess probably one of the Govs, maybe all the Govs benefit. If one Governor gets all the support, it will be Trump, that Gov, and Cruz. If all the Govs gain, then Cruz will take second and all the Govs to follow. Now SC is different, if trump is off by six that states politics would probably mean those supporters would go towards a more conservative guy. There is only really Cruz and Carson. I think Carson has been done since Nov, after San Bernedino, thats when the focus really shifted towards defeating ISIS and Carson wasn’t ready for it. Leaving Cruz, I see maybe one Gov coming out of NH with his candidacy still viable, with Rubio still clinging on hoping to do something in either SC or NV.
They won't be off enough for Trump to lose. They could be off enough for Cruz to come in fifth.
Cruz supporters best bet is if the polls are right on the money. Because as of this hour a second place finish is Cruz's absolute best case scenario in NH. If he comes in third or worse he's Newt Gingrich without Adelson, limping along until he runs out of cash.