I have 2 vft's that I bought early this summer. I have yet to transplant them for the first time. I live in Chicago where the winter can be pretty rough. My question is why should I put them in the frig if it gets just as cold outside as in the frig? Can I just cover them and leave them outside, giving them water just a little? My second question is when should I bring them in if I shouldn't leave them outside?