So I live in MN right now we are below zero had my car warming up before I head out to the store. Started my drive and vaping as I am going. I did notice that windshield was getting foggy again. I was ...? It stopped go into the store get my stuff (was in store about a hour) come back out inside my windshield has a nice layer of ice on the inside from me vaping. I had no idea water vape freezes on the inside. (I actually thought it was on the out side had the duro windshield washer spray going nothing.) Then it came to me. So I guess you still have to crack your window a bit to blow your vape out so you don't freeze up your windshield. At least when it's below zero and in MN that's half of our year. LOL 
