My update: I ended up getting an 18 once hydro flask. I preheated it with some hot water yesterday then filled with coffee. Had about an 2 1/2 hour ride in around negative 5 degrees with the wind chill each way. Only opened the flask about 4 times during the ride and the coffee stayed drinkable warm till around the 2 hour mark. On the return trip I filled it with water and the water stayed drinkable without ever freezing. Thanks for all the input, I’m very happy with my purchase