There is a ridge vent.
Ridge vents get snowed over, which means they provide 0 ventilation in snowy weather.There are windows on all 4 sides and what i wonder is, what weather temp At night should make me close all windows. I also have plastic i will wrap the run once there is snow in the forecast.
Without any additional vents (which I don't see any) some of the windows will need to be left propped open the entire time (obviously consider your wind direction and how protected each window is when choosing which ones to leave open, and still aim for 1 sq ft or more per bird). Consider adding more vents up high but under the roofline next year so you can close the windows if you want.