Id agree your easily 2 weeks, but personally id lay money on month if you go to full amber. If possible add more fans to keep that air moving really keep it moving, especially at lights out. Water at first light so the plant has all day to use up water. watering in the late afternoon or evenings can cause condensing humidity at cooler lights out temps. Watering slightly less on water days may help as well. Usually we water until it runs out the bottom, watering a little less so it doesn't run out the bottom may help with this as well. The down side to that is you'll be watering more frequently. A little extra defoliating may help as well, allowing air to circulate through the plant better. These are all little tricks that have helped me in the past. The good news is though your in the window now, let it go as long as you can but keep an eye on it and if it starts go south, you can harvest knowing you'll still get some decent stuff.