I did try here in what was zone 3, and now they call it zone 4.
They germinated in June, and there were green tomatoes in September.
But it might be an idea to try it again.
A different year with different weather?
And green tomatoes in September can ripen on a windowsill.
I don't remember which Variety------maybe really short season ones would work better? I'll need to go back in my Journals to see if I wrote down the variety.