From what I can find, you are in about a zone 4 b. I grew up in northern Manitoba and learned to garden there (a solid zone 3b, colder than yours. I'm currently in a zone 3a but can adjust microclimates to almost zone 5). The main thing to find is plants that will take excessive sunlight in the summer. Most plants can't take 20 hours of sunlight, so you need to find what are called "short season" crops. Pretty much anything grown has a short season you just have to check the "maturity date". You would even be able to grow corn to maturity.
Start what you can inside under lights. I found chard does pretty amazing growth in the more northern regions, from seed. Kohlrabi, cabbage, beets, radish and lettuce are staples, also from seed. I let my lettuce go to seed (around August) as it wants to bolt due to sun light, and then it self sows. "Hot crops" like tomatoes and peppers need to be babied a bit but there are tomatoes out there that will grow from seed to a small harvest before frost. My favorite is the open pollinated yellow pear cherry tomato. Leave some in the garden and whatever survives to produce next year will be the beginning of your own landrace seed.
For perennials, Sunchokes, Blueberries, Kinikinik, Labrador tea, nettles, mints, asparagus. I would try plums, apricots, nanking cherry, rhubarb (a staple), Ure Pear, aronia berry, chokecherry, pincherry. Look up anything coming out of the University of Saskatchewan fruit breeding program. Plants coming out of the Morden Manitoba research station will also do well for you (including some very pretty roses!).