Check out the post "Newly Constructed Greenhouse", I posted it just a couple of days back. I would be glad to share what I have learned. it's a GH which is attached to my house and uses a very ifficient and reliable GH covering.. Glad to help if I can !

If you are going to grow tomatoes in a zone 5 winter, you're going to be a very good customer of the utility company. Clear greenhouse coverings make very poor insulators of heat, and heat is expensive.

I would want some sort of an insulated blanket like a pool cover to throw over it at night or a system of insulated shutters that you can close. That's the only way to keep your expensive heat from floating up into the night sky. You have to be there every day to manage it, though, unless you spend a lot more money for an automated system. Those $20 "auto vent" openers don't take pool covers off and on.

I'd also want hid lights as supplements to the winter sun. Digital 1000 watt HPS or Halide lights are about 400 bucks. Based on that crop list, you'd want one of each. You can get smaller hid lights, but they are not much cheaper. They are very hot, which is not so bad when it's cold outside, but you have to vent the air when you don't need the extra heat.

Have I talked you out of it yet? It would be much easier to simply limit your winter growing to crops that tolerate cold weather.