The cold from winter can exactly diminish the problem of fungus spreading. Therefore, I advise you to remove the feuillage affected by the blackspot first. Please make sure you remove all dropped leaf and throw or burn them and not leave them at the base of the plant to spread the fungus.
When you are sure that there will be no threat of forst again, you can start to decide how to shape the rose bush. To prune and shape the rose bush, will stimulate growth, you do not want to activate, wakng up your roses and have the sudden frost kill or injure the new growth. Therefore make sure the frost threat is over before prunning.
Normally, for climbers, they will have more blooms when they are trained to grow horizontally. For others, the higher they grow, the lesser blooms you will get.
Spring peventive and nutrient sprays are very important to ensure a good structure of the plant. The preventive spray is especially a must right after spring prunning to ensure no effection to their wounds. Espom salt spray can be both preventive and nutrient spray at the same time.