If I ever need to stop very quickly, I try to end up in the "lane split" position, stopped in between two stopped vehicles. This has saved me from some nasty rear-end collisions a few times.
All it takes to swerve at speed is a small shove on the appropriate side of the handlebar, and 1m should be enough to put you either into the 'lane split' or into the other lane entirely.
I say this because I had a friend who was killed when another driver swerved into her lane while trying to avoid rear ending another car. In that case, rear ending the other car would've been way safer. So yeah, just be absolutely certain the lane you're swerving into is clear. That should go without say but apparently it didn't for the woman that killed my friend (and I bet she thought she was pulling off a ninja move until it was too late).