Gil,
I think Mike might be talking about extending the time for the poolish fermentation, and you might be talking about the fermentation time for the dough. If that's right, no need to adjust. One thing you could try, just to get a feel for how your poolish ferments, is make a small batch--like 150 grams--in a cylindrical glass, and just check in on what it looks and smells like every couple if hours. You'll see how it rises, how the size of the bubbles increases, how the fragrance changes, and then, as Mike said, how it collapses. How long that process takes depends on your flour and the various temperatures and humidities, but it will give you a better sense of the life cycle of your poolish and roughly how you want to adjust.