When it comes to pruning David Austin English shrub roses, as well as all hybrid teas, floribundas, and grandifloras, there are several important considerations to keep in mind before winter. You can lightly prune them to reduce the height and prevent the canes from whipping around in winter winds, but avoid heavy pruning in the fall. Prune only about a third of the cane length to protect the structure. A good rule of thumb is to prune between shoulder and waist height. I like to use the analogy that shape pruning is like a little bang trim rather than a full new haircut. 

 

You are correct in thinking that heavy pruning may encourage new growth, which would be vulnerable to cold damage. Light pruning, however, will not signal the plant to produce new growth but will instead help prevent wind damage and breakage over winter. Wait until late winter or early spring (just before the new season's growth starts) for more significant pruning. This will give you time to assess winter damage and ensure the plant is ready for a fresh growing season.

 

Old Garden Roses, like Madame Hardy, tend to be more forgiving and thrive with minimal pruning in the fall. Similar to English shrub roses, you can slightly reduce the cane length, especially if they are particularly tall, to prevent winter damage. Significant pruning should be reserved for late winter during dormancy or early spring. Since these roses often bloom on old wood, it's important to be cautious about the extent of your fall pruning and only prune those really wild canes.

 

So my takeaway for you is - light pruning on all types of roses (no more than a third of the cane) is fine now to reduce height and protect the plant from winter wind, but save the heavy pruning for dormancy in late winter/early spring (depending on growing zone). This will keep them all healthy without triggering vulnerable new growth too early.