From a mostly-automated solar farm orbiting Earth, a programmer with survivalist inclinations once ridiculed by those closest to him strives from afar to save his ex-wife wife and young son from the sudden outbreak of nuclear war.

You buried the lead: Start with the Nuclear War :)

But what exactly can the kid do? Unless he some kind of amazing hacker or programmer, it's not like the government is just going to give him access to the nukes to stop a threat they that they probably perceive as just a prank, plus he's the son of a joke programmer? ?And then, what's the point? It would be harder, and more interesting for the father in space to have to find a way to do whatever it is. And going along with that, if the son on the ground is the protagonist, what's the point of it even being sci-fi? This solar farm is supposed to be the advanced technology, but if most of the action is on regular old Earth anyway what's the point?
Personally, I just don't see much justification for making the teenager the protagonist. A stronger argument could be made for the mother, but only because it would be plausible for her to have government job having access, and thus being able to work.
Personally, if it were me I would probably make it co-protagonists, a buddy type film with the ex-wife and husband having to work through their differences to work together, one on Earth, the other on the solar farm, each having a specific task that depends on the other.

Thanks for the feedback. I like the idea especially of the hero instead being a?teenage son who, with help from his father, guides himself and mother to safety.