Valiant will take much colder than -30C, maybe -40C. It grows like a weed and while most of the long spindly annual growth will die during winter, the main branches are quite hardy even unprotected in zone 3 most winters. It tastes like a Concord... a seedy Concord :) Makes absolutely wonderful jelly, good juice, but absolutely terrible wine (at least the stuff I made was awful.) Beta seems to be almost identical to Valiant, just less hardy and less vigorous, at least the ones I've seen.

There are some new hardy varieties of grapes being bred at the University of Saskatchewan but I don't think any cultivars have been released yet. Something to keep your eye on though. Can't comment on the other varieties you mention.

Valiant fruit cluster:
{{gwi:93691}}

Thanks Don...

It seems super hardy here. I just took a better look at the valiant and it has a good 10 buds.

Even better, my Himrod has buds a foot from the ground, and so does my Vanessa! These arent against a wall, and are on mesh exposed. Good thing we had a foot or more of snow this winter!

I should probably ask as well... The Himrod and Vanessa have are in their third year. They grew to about 3 feet last year, but didnt have too much vigor. Any tips to get these guys growing well?