Silly question indeed. Poor thing. One of my Split Leaf Philos. I cut off 90% of old roots. Now in a slightly larger pot with new soil mix. Should respond well. About a month to go before it has to come back inside. Actually above ground wise, it was looking OK.
Very often, you can't tell a plant is suffering by looking at the foliage, especially if it's suffering from tight roots. When you start seeing a lack of extension/smaller leaves.shorter internodes, and often an absence of foliage except at/near apices, it's time to repot (not just pot up). There's no doubt your plant was in serious need of remedial root work. Shorter days will inhibit the response you'd have been able to see had you undertaken the task back in June, but there's little doubt your plant will show its approval.