They will survive and grow well inside on a warm sunny ledge.unless your temps are going to get into the 80s I wouldnt even bother moving them outside

They could survive over the winter but not in a form you'd like. ( smile)

They're going to get bigger and bigger and bigger, so what you'd have to do is to take cuttings from them and root them, let those plants get bigger, take cuttings again and root and time the whole thing so you have plants that are perhaps 6-12 inches tall to set outside when it's time to do so in your area.

There are some folks who do overwinter a few varieties in the manner I just described, but very few.

There are two problems I see.

First, you have no idea what your miracle seedlings are from that compost and it's a lot of work taking the cuttings and rooting, etc., that long and then get tomatoes you don't like at all. Perhaps they might be seedlings from a hybrid and being a hybrid initially you'd be growing that hybrid from F2 seeds in the compost. On the other hand it could be fun to do to see what you get.

Second, overwintering seedlings by taking cuttings and growing without additional light isn't going to give you the same strong stems you saw with your volunteers.

When you raised your own plants from seed were you using a light set up to grow them?

Carolyn

Absolutely no reason to go all winter without homegrown's if you have a sunny window. For many years now I have grown delicious tomatoes indoors in a sunny window without additional lighting. New Big Dwarf, Kotlas, Momotaro, Red Robin are just some of the varieties I've grown successfully indoors. This year I have a huge Big Sungold Select in a window with a dwarf Red Robin and basil plant going. Below a pic of Momotaro in the window. No disease, no bugs, no problem....