I don’t have a winter crop, a separate grass in the winter. But while most people here in SC just quit watering after the first good freeze, I’ve heard it’s a good idea to keep the ground from getting too dry over the winter. The grass might not die if you don’t, but it will recover better if you do.
So I, using my Flex Daily schedule, change the Crop Coefficient for all my zones. The default value for my Centipede grass is 85%. If I lower that to 50%, it will only put down 59% as much water as it normally would for “live” grass, while my grass is dormant. Rain is still considered normally, but it uses less water and keeps the ground from drying out so much. Likewise, I change either the root depth or Allowed Depletion to about half the value (say AD changed from 50% to 25%). That doesn’t change how much water the lawn gets per week, but will water twice as often, which in winter, might only be once a week or so. I think that’s better than going maybe 2 weeks without water.
I make notes of the changes I’ve done, and put it in a Calendar reminder for March 15, about the time I’ll either go back to normal settings, or based on weather and conditions, wait a bit longer.
Not all that scientific (and I DO loves me my scientifics), but it seems to work.