My favorite garden was in zone 5, 100 X 100 with perfect silty loam soil. No need for a hothouse/greenhouse. Plenty for a family of 4, fills a nice 10X10 pantry with root crops/canned vegeys/dehydrated/frozen plus enough to give friends, the food bank. Had perennials like asparagus, horseradish, raspberries, boysenberries, strawberries and artichokes.
Now I've got a greenhouse of 1200 Sq. ft. Zone 1b, seriously insane. My soil had to have yards of decomposed organic matter added. Every month of the growing season has had a freeze or two. We still had an awful lot of produce and preserved vegeys. And we haven't heated the greenhouse for the past 4 winters. Next year, finally (rocket heater). Perennials such as herbs, strawberries, vine berries, Asparagus (takes 3 years before you can harvest), raspberries, blue berries. Are you doing a poly hoop green house or a kit or dimensional lumber?
We use the soil beneath the greenhouse as a garden with raised beds (1' high 3 or 5' across, 3'main walk, 1' walkways between the beds, 3' beds all around the periphery), trenches for drainage and have a few crops in pots like tomatoes, peppers lining the main walkway. We have a little heated green house for producing all our starts earlier and to drag all the potted stuff inside at night (argghhhh). I don't do straight lines of vegeys, I make use of every square inch. Broadcast or 'sheet farming'. Way more production. Plenty of room for rotation every year. Cover crops in between cash crops. Worth the time and effort. Is your greenhouse visible from the road?
There is one book you should buy as well as others but make sure you read Shane Smith's Green House Gardening!