The windows definitely need replacing by the sound of it, but using plastic sealed at the edges over the windows will stop the problem, by and large, but obviously means you can't open the windows till spring. The other thing that might help is leaving your bedroom door open all night - breathing and body heaat create moisture, and that condenses on the cold window panes, even if the air isn't too humid already, so leaving the door open may help to disperse that humidity.
I recall as a child (unheated houses other than a central fire in one room, single glazed windows) my parents and grandparents putting newspaper on the inside of the window panes when condensate appeared to soak up moisture, replacing it once it was too wet. Once into proper winter, the condensate on the inside of the windows froze, creating some rather wonderful patterns, not something commonly seen now. Those were the days when you left your clothes for the next day on the end of the bed, and in the morning, pulled them under the covers to warm them and got dressed whilst still in bed... certainly not something I'd want to do as an adult.