If AGI were coming in a year, what should we do?

Honestly? If that is the case just act as if you have some painless terminal disease and you have one or two years to live. Do a bunch of things you've always wanted to do, maybe try a bunch of LSD to see what that's about, skydive a bit, make peace with your parents, etc. 

At the one year mark I don't think the overton window contains any actions that would actually be effective at preventing AGI. Which leaves us with morally odious solutions like:

1.  A coordinated strike against all AI labs in the US and Canada, but even that doesn't actually buy that much time if all the key insights were published, it'll just mean that China gets there shortly after.
2. Provoking nuclear war between China, Russia and US while having some secret bunker base with enough survivors to outlast whatever fallout there is, maybe relocate all AI safety researchers to New Zealand? 
3. Release a deadly pandemic? Maybe use crispr to have it target people based on dna, which you've collected by giving our free lemonade at AI conferences?

As you see, the intersection between the set of pleasant solutions and the set effective solutions is empty if we're at the T-1year mark. All the effective solutions that I can see involve killing lots of people for the belief that AI will be dangerous, which means that you darn better have an unshakeable degree of confidence in the idea, which I don't have.

Try to figure out the best possible defense-in-depth strategy.

In other words, there's a whole bunch of different proposals for safety. I think it'd be worth thinking about what would be the optimal set to stack on top of each other without them interfering or requiring unrealistic amounts of processing. It'd also be worth thinking about a more minimalistic set that would be more likely to be implemented.

Maybe create a Slack or Discord focused specifically focused on the imminent threat as it'd seem valuable to be able to have these discussions without being distracted by discussions that wouldn't be useful for the immediate crisis.

At a certain point the best strategy becomes physically preventing AI organizations from developing AI, somehow. You could do this by an appeal to governments, or we could pour lots of money into the new EA cause area of taking over the computation power supply chain.

I am not an AI safety researcher; more of a terrified spectator monitoring LessWrong for updates about the existential risk of unnaligned AGI (thanks a bunch HPMOR). That said, if it was a year away, I would jump into action. My initial thought would be to put almost all my net worth into a public awareness campaign. If we can cause enough trepidation in the general public, it's possible we could delay the emergence of AGI by a few weeks or months. My goal is not to solve alignment, rather to prod AI researchers to implement basic safety concerns that might reduce S-Risk by 1 or 2 percent. Then... think deeply about whether I want to be alive for the most Interesting Time in human history.

I'd try to survive the year, on an off chance that the AGI will be able to solve aging/uploads and let humans live for as long as they want. Sadly, this is not an option for a 2+ years horizon, as the pandemic demonstrated so amply.