Film is just a band-aid if the windows themselves are the real problem. Condensation like that usually means the windows have lost their effectiveness and aren't insulating properly anymore. Single pane windows especially can't keep up no matter what you put on them. Looking into what a proper window replacement service would cost https://windowtechcanada.ca/how-to-determine-window-replacement-cost/ helped me understand that replacing them was the actual solution. New double pane windows completely eliminated the condensation and mold issues