Think about the fact that characters are used in texts in two ways: as psychological beings undergoing change and evolution; and as vehicles for thematic messages and exploration.
Iceland can't have the former, because it's not a person, so it can only have the latter - can only fulfil that function. Therefore, saying it is a character is saying it has "personality" traits that connect with and explore one or more of your themes.
Therefore, start by brainstorming what "personality" traits Iceland could be described as having - how would you characterise or describe the country, landscape and weather? Then, go through and connect those traits/descriptions with themes from your theme notes. An easy way of dividing BPs would then be to explain how Iceland's <blah trait or traits> explore/communicate/represent the idea of <blah theme> - one per BP. That's not the only para split, of course - it's just a fairly straightforward one. And it also gives you an argument to make in each BP... and, an argument that lets you pretty easily integrate your evidence on Kent's techniques for personifying the weather and landscape.
You could of course just go through traits, one trait per BP - but without connecting those traits to meaning in any way leaves you with just a descriptive paragraph. Which you don't want, because describing is just telling the story.
At the moment I think there isn't a logic linking the three ideas you've noted down - they overlap, but kind of all go towards the same point from different angles.