I've already put my tomatoes out in the unheated greenhouse. Well, had to put heater out there a few nights when it dips into the 30s. but otherwise, they're out in the cool nights. It does make them stockier. And that way I don't overwater them since they're not in my face all day!
Every year I say I'm not going to overwater, and every year I still do! And I've been doing seeds for a lot of years.