I flew through the whole of last winter once a week, with only 1 or 2 being cancelled.
Early lessons at say 9 o'clock gave me crisp smooth weather and on the odd occasion there was low cloud, we got up and done some bad weather circuits or low level navigation.
I was probably lucky with the days I chose to fly and in all fairness we did have quite a mild winter.
I done 1 hour per week, some say this is not ideal in terms of progression, but I soloed at 11 hours and currently at 34 hours am preparing for the qualifying cross country.