After reading
http://www.kdcomm.net/~tomato/Tomato/start.html I also had some questions regarding cold treatment, especially since last year I planted just one tomato plant in the ground on 7 april, three weeks too early. Just to see what will happen. Last april was frost free, but temps were often in 40's. Plant survived, flowered and I've never seen so much flowers on one truss before.
Sadly it was a spitter, Moneymaker, which I got free from Thompson&Morgan and planted of curiosity, but experience was very helpful.
I have one bright SE facing unheated room where temps are just right for cold treatment and this is the way I'll go this year.
Here's a picture, there was 16-18 fruits on one truss, and the plant was pruned to single stem: