Losing weight is impossible in winter, IMHO!!
The darkness, extreme cold, short days, etc., greatly limits my exercising, and I think your body goes into a "winter mode" where it conserves body fat to protect you from the cold.
I have no scientific basis for the above, just my humble opinion.
I am trying to ride the trainer 45 minutes/day, but it just is not the same as outdoors biking.
Brr! in Denver!