Sun instead of lights? - Newbie

[JoeP]

This is my second year gardening and I'd like to try starting some tomatoes from seed. I've read through a few related threads about lights. I'd like to know if anyone just uses low tunnels (PVC hoops with plastic cover -unheated) instead of shop lights inside the house?

I ask because my only south facing window in my house is not safe from my 2 small children (3 & 2 yo). I could use lights on my workbench in my unheated, un-insulated garage (connected to house) but I worry about nighttime temperatures getting too low. I suppose lights inside would be much more convenient than carting a flat of seedlings in at night and out in the morning.

I spoke with two growers at farmer's markets that sell tomato seedlings (thousands of them) from unheated greenhouses. Could my low tunnel work the same?

I am guessing this question has already been asked so feel free to point me to an earlier thread.

Thanks in advance,

Joe in cool, wet, western Washington
25 or so planned tomato varieties