California, I'd say yes there's more than enough time. Illinois, on the other hand, I'd say tough luck there Sonny Jim. My Mum lived in Rock Island when she was a young lady before moving to the U.K and I've heard about the winters you have there. Without 4-6 weeks development, even with a starter fertilizer, the grass you lay down won't be strong enough to survive the cold. If you think you can squeeze out a few weeks before the lows dip below 16 C** then go for it.
**( that's about 60F)
I don't seed a day past 4 weeks before the first expected frost, which is October 15th (first expected frost date is Nov. 15th). I few years back I could have seeded into November and been ok, but you just never know for sure.