I did blue dream in '10. I pulled mid oct but I pulled early. Didn't hve a scope at the time. I would look at it oct 28 and pull the morning of the 29th if trichomes are cloudy. If they're still not ready, just keep an eye on them. Maybe early nov? But I doubt I pulled 4 weeks early. I got high off it for sure. Rolled a j in the back of the bus and the whole bus was complaining.. Lol when I got off bus driver was like "You seem like a nice enough guy but I cant have you smoking weed on the bus."
Good luck man! I'm thinking you should circle 29 on your calendar. I always pull on the full moon if they're ready. I heard it increases resin and thc strength. Usually full moon is mid oct but I think this is the year of the sativa hybrid! Btw, I'm at around 38 deg