Longest your same tomato plant kept producing?

[garyc1234]

I live in the Bay Area in Northern California where the temperatures are pretty moderate all year round. I've noticed that some of my tomato plants that pretty much "died" are actually giving out new stems and are looking green again. (I've attached a picture with one example.) I'm thinking of trying an experiment to see how long some of these plants last and whether they will give another productive crop. With the temperatures in the Bay area, we might not have a frost at all, so it's possible these plants might be completely fine.

I'm just curious to see if anyone else has tried this (in one of those regions where frost is rare or inside a greenhouse). This would be the same tomato plant with the same original root system and not a new planting via a sucker from the original one.