The goal of an initial adjustment would be to remove about 1/2 NET delta. So if SPX rallies and my NET delta is -40 I will look for an OTM call with a delta of 20 or so. I wouldnt want to remove ALL of my NET exposure because an Iron Condor is a mean reverting trade. If I’m forced to adjust that means the underlying has moved far enough in one direction and is probably going to revert a bit (that typically happens as soon as I adjust), however, if it continues to move in the same direction then I will roll up the ‘bad’ spread and close the hedge.