I tried growing Siberian tomatoes outdoors in Anchorage for a couple of seasons.  

I would start them from seeds, indoors, and transplant them outside on Memorial Day. I got lots of green tomatoes, that never turned red in Alaska's short growing season.  I read somewhere to wrap them individually in newspaper, and put them in a paper bag under your bed.  I did this and, one by one, the tomatoes would ripen to perfection, every day, over the course of six weeks. 

Try this! I don't know if they  necessarily have to go under you bed, any warm, dark, dry place will probably do.