High Tunnel/Hoop House

a simple construction hoop houselarge commercial hoophouse for growing tomatoes

If you have a bad case of zone denial, this simple structure is an excellent starting point, if not absolutely essential.

Altitude

High places cause their own extreme conditions, from UV damage to rapid changes in humidity.

Temperature

You can get heat tolerant variants, but there are limits...
Cold hardy is one thing - growing in the snow and ice another altogether!

Blog:
Extreme Gardening

Extreme gardening blog links here.