While I was stationed at Schofield Barracks in Hawaii I would find tomatoes and peppers out in the "boonies". Some of the plants had 6-8 inch trunks. Mainly the peppers if I remember right. Depending on the time of year the tomatoes would be sweet or mealy. Peppers were mainly chilies of some kind.
I have a room I start my seedlings in so I plan to clone a tomato and see if I can keep it alive along with a couple of pepper plants. May even get a tomato!
I hope this helps,
James

Any indeterminate variety tomato can be grown as a perennial but it can be an expensive experiment depending on the set-up you have.

We have greenhouses but decided years back that it just wasn't worth the time and the expenses of heating the environment (they are tropical plants after all ;) and providing sufficient lighting (takes a costly halide system to get fruit) given the small amounts and the quality of the fruit produced.

If you don't want fruit, then yes you can keep the plant alive with just sufficient heat - say growing it in the house in a very sunny window - but then pest control becomes a problem. You get a long, lanky plant that you can root suckers off of the following spring if you wish but other than that I have never found over-wintering to have any benefits. New grown seedlings in the spring will quickly pass it up in both growth and production.

JMO

Dave

Thank you for your informative replies. They wisened me up a bit....

I happened on a TV gardening program and there's this incredibly successful gardener in Alaska!! growing tomatoes in his little greenhouse supposedly with fruit year-round....

My own Brandywines are superb this year, and I blame them somewhat for taking me down this road of gullibility, because having them year-round would have been soooo good. I need'a snap out'a it.

Will save seeds instead.....

Dave, I do indeed grow a couple plants in a sunny window through the winter. No lights whatsoever. Seeds started around August 1. For many years I grew Red Robin. The last two years I grew Momotaro. This year I'm growing New Big Dwarf as I've come to appreciate that smaller plants are better because I have less pruning than with a huge indeterminate. (But I will miss my winter Momo's!)

My plants are only a little leggy and produce many fruit through winter and I've never had an insect problem indoors on tomatoes. Many years ago I had mites on some indoor ivy though...:)

Here's a pic of last year's Momotaro:

I recently received some fruits from a cherry tomato the owner says has been producing in a container here in SoCal for 4 years. He said production goes down in winter, but he gave me outdoor tomatoes in February, which is impressive. I am planning on saving seed from these fruits and growing them out this summer and seeing if any survive through next winter.

I also have one volunteer tomato plant that survived this winter so far relatively unscathed. If it produces this spring, I will save those seeds.

I figure that tomatoes have mostly been grown as annuals for at least 200 years, so some of their perennial characteristics have been selected against. Within a few generations of breeding, it should be possible to breed an indeterminate tomato with a more favorable perennial habit.

Specifically, I am interested in a long harvest season, some degree of frost tolerance, a short dormant period and an early return to production in late winter/early spring.

This has been my experience and it was kind of random, so take it for what it's worth. Also, I am in AZ,so we have very mild winters.

We found a random tomato growing in our garden area in Oct. It set fruit and was growing well until temperatures dropped in Dec. Because it had already had a bunch of green tomatoes on it, I thought I'd try and keep it alive just to salvage the fruit. It rarely gets below freezing here, so they were fine most of the time. We did cover them with sheets at night when the temps dropped down into the 20's for a few weeks. About half the plant died off, but most of the fruit still stayed good.
By the time the temp started warming up, We had a half dead plant with lots of green tomatoes. I cut off the dead parts and buried the stems in the ground. We did get most of the fruit to ripen up in Feb., so we had tomatoes by the end of Feb.

We kept the plant and new shoots started growing. We had a few beautiful new plants growing and flowering by March and fruit in April and June. It was fabulous.

Now that it's July and the heat is consistently above 100, the plant has stopped producing and is getting leggy, but I plan on doing the same thing we did over the winter. Cut off the dead parts and cover the stems. Hopefully we'll have fruit again come Oct/Nov.