Does cold weather affect duck egg production?

I have 3 Khaki Campbell ducks born last spring. Up until this past week they had consistently laid 3 eggs every day with very few skips.
This past week there have been 2 eggs most days, but zero eggs yesterday, and only 1 today. It has been cold here- teens to single digit temps, with windchills below zero. The ducks have a house they go into at night, but choose to stay out in their yard all day. They do a lot of sitting, but still seem to be active. They have free choice layer feed, with fresh vegetables 2-3 times a week, table leftovers, and a bit of whole corn or wheat berries every afternoon. Do you think the cold is affecting their egg production? Should I supplement with something else?

Thanks,

The Yard Farmers