Thank you so much! Your site has been helping us so much as the local suppliers often use strange names for the bare root roses and we often turn for help here.
It takes some extra work for winter-spring protection and the main danger comes not from the frosts, which have been seldom lately, but from the greenhouse effect caused by snow rapidly melting and freezing causing roses to sit in pieces of solid ice in the bright spring sun. They usually just "get fried" and destroyed by cane cancer and other fungus in the spring.
I build waterproof winter sheds for each rose bed - strong wooden frame with plastic film covering leaving the narrow sides open to let the air flow. By covering them with plastic as early as in mid-October, I keep the flower beds dry through the fall rains and my roses go into the winter dry. I cut tea hybrids and pin down the shrubs and climbers, cut off all leaves, spray with fungicide and cover the plants with fur tree branches for frost protection. When it gets really cold (December), I enforce my plastic covers with more staples and pieces of roof felt and similar materials, still leaving the sides open. In the spring I remove plastic, but keep some fur tree branches for protection from the spring sun or replace with a light landscape fabric.
I used to live in Los Angeles and amazingly I find it EASIER to care for the roses here in Russia as there are less brutal day-night temperature differences, easier to fight off the pests (don't even need to spray, just pick aphids with gloved hands) and disease (just 2 fungicide spraying per season) due to healthier and more balanced ecology of my garden where I keep chemicals to a minimum. For example I make my own sprays using weeds such as nettles and common horsetail and fertilize with horse manure hand picked (literally ! :) at a local stable.
The roses don' t get as much sun here and don't grow as fast, but still are so much fun to care for!