From what I’ve been “told” here on FR is that Iowans are not deterred by the weather, so why would it have any effect in any candidate’s supporter’s case? I do not think there is a causal relationship with one group and not the other...and if that thought exists, I’d be interested in hearing why...
I lived in NoDak for awhile. Weather deters Grandma and Granpa who might slip on the ice. It might deter a few people who are marginally connected to their candidate.
It’s enough for a +/- 5% swing, IMHO.
But we don’t know which way that will cut. Who is more motivated? Cruzers or Trumpsters? Not Rubes. :-)