If you don't get much frost, some vegetables like spinach can grow outside the hoop house. They are frost tolerant. Just let them thaw out before you harvest them.

Others, like brussels sprouts, actuually taste better if harvested after a hard frost.

I would do succession planting - a couple weeks apart.

Spinach is a cut and come back veggie, along with the lettuces. If it gets too hot, it will bolt and you will have to plant again. Personally, I would plant some inside and some outside. Seeds are cheap and the knowledge you will learn is worth so much more.

I have a bed of lettuce and spinach growing in my high tunnel now. I am going to start to harvest it tonight for market tomorrow. I also just planted a small 12 by 18 tunnel with spinach. I am planning on seeing how this stuff grows. I also am doing an experiment with some lettuce and spinach planted in a half 55 gallon plastic barrel. If I can get it going, my plans are to leave it in the tunnel then bring it into the house and try to maintain some greens in the winter in the house.

Seed is cheap and learning you can grow in the winter is so neat.