In Hawaii, without frost, I usually cut the roses in January. I have to cut the tall canes down anyway or the growth will just be spindly. January is a good time to do it because it is when we have the most rain. I have less disease problems if the roses are opened up and cutting the canes lower will give me stronger growth. I do use pruning paint on my cuts because I had a problem with dieback and it was recommended by the J&P rose hotline. I have a lot less problems with dieback now. It also helps to make sure the tools are clean and sharp.