Its simple. Just have these goals:
Swim time: don't worry about it
Bike time: don't worry about it
Run time: don't worry about it
Overall: Race smart and kick ***!
Worrying about times only sets you up for failure. You train hard... VERY HARD... so you don't need to worry about times, you will be confident in your ability. Race the race you've trained for, its a long day, too many things could happen which are out of your control, so don't waste energy worrying on a time and conditions. Race the race you trained for and the time will take care of itself.
That said.. anything over 11 hours and I'll be disappointed See ya at the finish!