Twisted outdoor (established) leaves - Due to cold temps?

Yes, the cold is not favourable, it will slow maturation, but as long as you don't get any frosts, they will continue maturing. Minimum 70% brown pistils for any sort of appreciable effect. If you could erect a removable cover of shade cloth or something similar to protect them at night, this would benefit them greatly. If they are in pots, placing them against a south facing brick/stone wall that can radiate heat at night, would also benefit them. I would not worry too much about the twisted leaves, just worry about frost, this is a real killer, but it can be mitigated by erecting a removable cover of some sort. I don't get snow where I am, but have grown many plants in mid winter just for fun, with day temps less than 10 degrees C (constantly) and night temps down to -4C on ocassions, and although growth and maturation is slow, they can still thrive as long as not affected by frosts, which causes irrepairable damage. By the way, growing mid winter is a great way to produce seeds from regular plants and/or harvest males without having to worry about pollen affecting your summer crops! The seeds turn out fine and are just as healthy as summer produced seeds, only fewer in number due to the plants being smaller. Hope this helps, Organoman.