Growing "warm season" vegetables in cold climates

I have a vivid memory of seeing foldable glass protectors over squash and cucumber seedlings in England.  They were apparently meant to provide a bit of "greenhouse" warmth for what I'd grow as a warm season vegetable in the Southeastern U.S.

Growing tomatoes there -- well, that was a greenhouse endeavor, as far as I could tell.

I loved this small greenhouse full of tomatoes in a rectory garden.

Here in Quebec, I'm musing about how folks manage to grow any tomatoes or peppers.  I guess you're hoping for a heat wave in July and August.

These are lovely temperatures for outdoor activities, but not particularly squash, tomato, cucumber, or basil-friendly!