Well i delivered my daughter her being 9pounds 3ounces 22inches long but they think he might be bigger than that and dictor said that they massage the baby in to birthing position under ultrasound monitoring
Your doctor is putting the option out there so incase it happens you are prepared. I have to have another csection and they really aren't that bad. Maybe your doctor feels your birth canal might be on the smaller side compared to another woman's. Just relax and see what happens, if your baby hasn't turned by your due date than most likely you may have to have one. He is running out of room so the chances of turning himself to get smaller and smaller.
Ultrasounds are very inaccurate when your this far along babies have been measured out to be 9lbs or even bigger and then when baby is born they were only 6-7lbs. Your baby has lots of time to turn the ONLY time you NEED a c section for this situation is when you go into labor and your baby is still breech. There is no reason for talking about a c section at all. And I have never heard of "vaginal delivery tolerance" plenty of first time moms have delivered 11-12 pound Babies.
As far as dilating I wouldn't worry about it I hear you can be at a 1-4 for weeks and nothing happening so if you're not dilated yet I wouldn't worry, as for being breech if he doesn't turn in time and if the doc thinks he is too big I think you do have to get one. My appointment is tomorrow I'll be a day away from 36w and I'll see if he's still breech (he was last week) if you do end up with a csection don't worry it would be a longer recovery but think about at least you don't have to push and be in labor for hours and hours! Hope I helped good luck Hun.