I live on the other side of the Valley in NOCAL at the 2000 ft. elevation and haven't lost any roses due to the extreme temp changes in the spring. I think it is a matter of culture more than environment. You cannot imagine the range of advice I have received since I moved up here. Some people actually prune roses in January !

Here are a few things I have learned by my own experience:
1 Do not feed roses anything with nitrogen, not even organics, after October.
2 Only fall prune to prevent snow breakage ... and that's only to top prune more than anything else.
3 Always expect that you will have hard frosts in spring.
4 Don't prune until danger of hard frost has past. If you do see frost damage, ignore it. To cut it off too soon only tells the rose to put out new growth, which will be killed by the next hard frost. Wait until the rose leafs out and then prune out the damaged canes...generally down to where the new growth starts. (you can removed obviously dead canes down to the bud union before the plant leafs out)
5 Don't feed your plants too early in the spring as that encourages new growth.
6 When you do prune, prune lightly ... you have a shorter growing season.
7 Don't count on spring rains to water your roses. Dehydrated roses are far more susceptible to cold damage.
8 When you water, even during the summer months, make sure you water in the morning before it gets hot. This slows down the transpiration rate the plant experiences later in the day.

I have grown over 100 different cultivars of many classes and the only rose I lost was due to the fact that the pot I had it in while waiting to find the right spot to plant the rose, did not drain well and I virtually over-watered the rose and killed it myself. I don't think the dramatic temperature changes we experience is all that hard on the plants as I expected them to be.

All of the above is for someone growing roses at 2,000 ft elevation.

Smiles,
Lyn