This past fall, my first time growing tomatoes, I was wondering the same thing you were, OP, about when to pull them. Because even into September my Early Girl and my 'Tomato' plant (seriously, I bought the plant at Home Despot and that was all they called it . . . the nursery's colors were yellow and green, can't remember the name of the plant grower -- but it was a really good plant, tons of tomatoes and they tasted a lot better than the EG . . . I digress) . .
Anyway!
My two tomato plants were producing well into September and even into October (green fruit left and right!) and I couldn't seem to get consensus on when to pull them -- but then the decision was taken out of my hands.
One day it was 65 and sunny, overnight the temp. plummeted to 25'F and the next morning, there was an inch of snow and some dead tomato plants. What a sad sight that was. Without warning, we'd gotten a killing freeze overnight and it killed my warm-weather plants stone dead. My green tomatoes were actually frozen solid on the vine.
The next day that it wasn't snowing and cold, I pulled all the plants that were left and put them on my compost heap.
But that's my climate, and I certainly don't live where you are -- not anymore, anyway, as a kid I lived in Poway (a suburb of San Diego) and we had beautiful lemon, lime and fig trees!
Why do you want to pull your plants? I saw online, when I was searching about tomato information last year, quite a few people who lived in warmer climates and they treated their tomato plants like a year round producer. One woman even had her indeterminate tomato trellised (or maybe, vined? Not sure how she did it) all around her front door to her home, it was really pretty -- and useful too!
I wouldn't have pulled my plants if I didn't have to, so I feel for you
Whitewater