Pruning a tall bush rose

I've got several shrub roses of the sort that grow into tall upright bushes, 6 to 8' tall. They are sold as climbers but they don't climb really. One is called something like Dreaming Spires, another is Summer Wine. Now the rain is fast washing out the flowers will they object if I prune them hard, down to about 3'? This'll mean cutting off all the main branches and just leaving a trunk. They are not repeat-flowering so it seems like a reasonable time to do this.

I need to create some space in my rain-sodden plot. Anyone got any experience of doing this?

 

Haven't done it intentionally but did have something similar happen after a storm one year. I was away in June but my neighbour told me that some of my rose branches had broken off in high winds so she tidied them up by taking the secateurs to all of the damaged branches (most of them). She also stuck one of the broken branches in the ground in her own garden. The bush was a Dublin Bay which is similar to as you describe; sold as a climber but more like a big bush.
The next year mine flowered beautifully - and so did hers!