The phrase "winter mode" means the way we adapt or prepare ourselves for the winter season, such as wearing warm clothes, using heaters, or being cautious on slippery roads. Full definition
I'm still fully in winter mode because the temperatures shot back down this past weekend! (violettedaily.com)
Next week's grocery will tell if I will buy more or get into winter mode. (chefdehome.com)
For this month's series I thought booties would be fun since we're in full on winter mode and I literally wear booties non stop all winter long. (pearlsandtwirls.net)