Photographing the aurora borealis... with a smartphone?!

Hi chaps,

I'm here because I need some advice. I'm going to see the Northern Lights in a few weeks and am unsure whether to invest in a new camera for the expedition. I moved away from using a dedicated camera a few years back due to needs changing, but this is a very particular situation and I'm a bit conflicted.

Me and my partner will be armed with both a 1020 and the iPhone 5S, and from what I've gleaned, as top of the line camera phones these should be able to take some "decent" photos. I just want to know what the benefits of say, a Canon S100, would be compared to what we're using at the moment.

Many thanks for the help!