Is it too early to panic about your team, or is mid-November the real cutoff?

We're a couple weeks into the NBA season and every year I swing between 'it's a long season' and 'this roster is cooked'. The common wisdom is you don't really know anything until around 15-20 games. But some teams clearly show their identity in the first 10. What's your rule for when early-season results actually mean something?