Any 2, but this is because even if I were to get down to 4k in the hand, I'm confident that with 20bbs, a slightly larger than 2:1 HU deficit isn't a bad spot for me with the reward to hitting gin and stacking the SB were he to have something he can't get away from.

But usually, it's 300 to take out a player and get a little more for HU play. If the microstack triples, he can be the punching bag on my left and I'll get it back because getting up to 1500 gives him a shot again. This is usually how this scenario unfolds for me.