To determine whether your windows are drafty, try placing a burning candle by the window's edge on a cold day and see if the flame flickers. Although you need to spend money on repairs, it will help save on energy bills in the long run.
We had a rental that took water damage due to a roof leak. Arteco was able to get in there next day and replace the drywall, insulation plus paint within 5 hours, this should have been a 1.5 day job....