Great question. I have not looked specifically at the commonalities in terms of the atmospheric conditions themselves. It'd be a great topic of research, though the sample size might be too small so it'd be hard to draw conclusions. Usually though, double warming events occur 2-3 months apart so there's time for the stratosphere to rebound.  During 4 of the previous 6 double events, the first warming occurred in December.

If this event unfolds as forecast, it'll only between a month between events, which is interesting because it usually takes longer for the stratosphere to recover. However, the event last month was not typical because it started in the lower stratosphere so that might be a factor.