yes Jim, here we use green polyprop netting as windbreaks. Similar stuff is also used as greenhouse shading or even making a shade house. This is really useful stuff and can handle any amount of crappy weather. The trick is fitting decent posts so that netting can be stapled into place. I have a long (15m) line of this, about 1m high, in the lee of which I put all this years new perennials (seeds and cuttings) to overwinter since it is usually East Anglias fierce easterlies which does for a lot of plants. A much lighter weight material is white horticultural fleece. This is usually just laid over plants although I have whipped out my sewing machine and made little winter coats (honestly) for plants such as melianthus and even my globe artichokes.
Finally, we can buy a white nylon mesh called environmesh in the UK which does sterling duty as a pest barrier on brassicas. My whole allotment looks quite odd in winter with numerous timber supports and various meshes tucked here and there.

Id like to try a special fabric sometime for my climbers. For now I just wrap them in three layers of burlap after untying them from the trellis. I tried just laying them down and covering them one winter, but the voles had a feast. Now, when I mound the base and before I wrap the canes I put mothballs and Bounce fabric sheets at the base which seems to discourage the voles most of the time.

I know there is a lot of stuff about right plant for the right place and so on, but you keen rose growers who have to do this annual untying, wrapping, mounding and so on, really represent the true spirit of gardening, I think, with your heroic efforts to push the boundaries and experiment. All gardening is artifice anyway so lets hear it for those determined growers.

I've been wrapping my rose arbor with white polypropylene seed cloth--I got a lot of it really cheap at White Flower Farm's annual sale some years ago. It looks nicer than the burlap I used to use.

campanula,
Your "any amount of crappy weather and fierce easterlies" are a lot warmer than the bitter below zero F cold of Jim's NY winters. Zone 5a average lowest winter temperatures are minus 15 to minus 20 degrees F ( -26 to -29 degrees C) compared to your UK Cambridge average lowest winter temperature of +3.4 degrees C ( +38 degrees F). This indicates you don't experience a freeze, while zone 5a can experience 2-3 months of below freezing temps (+32 degrees F), many days of which are below minus 17 degrees C (0 F).
What may work for you may not begin to protect Jim's roses where the soil can freeze quite deep for much of the winter.
(note; Cambridge UK lowest winter temp taken from this website, http://www.colc.co.uk/cambridge/cambridge/climate.htm )

Having said this, I've seen leaves surrounded by burlap used to protect roses in zone 5a. I suspect the burlap protects the roses from the bitter cold drying winds more than the cold temps.

Karl, you're right about burlap (and most likely other landscape fabrics) protecting canes from wind, not cold. The winter cane loss I experience with unprotected climbers is from dessication. Some of the hardier climbers can take the cold, but the drying winds do a lot of damage. I think that's why my potted roses that spend the winter in our freezing garage do so well - they are out of the wind.

Glad I posted this as there are lots of good ideas to try. Mostly about other kinds of fabric such as the horticultural ones. But I was really thinking mostly for protecting a few "specimen" roses. Not only from winter but also from deer that we have lots of here in the country. However I might try some Z6 roses now especially climbers,

Well Hey Karl, I have just been whacked with a very uncambridgelike -14. I managed to fleece my greenhouse but not until my aeoniums flopped to the staging. I expect there will be a few salvias I won't be seeing next year either. And the garden - ha...and it is a tiny little sheltered walled one too. I have not dared inspect the damage at the allotment which has no shelter and is in a frost pocket. The entire amount of soil in my garden is frozen solid. However, there is one major consolation - the daily dog flower removal is much, much easier with frozen poo.

Your UK website is not very accurate or you're experiencing very unually cold weather. We've got to start talking the same language, either metric or US standard or at leat post both so all can understand. -14 C is +7 F and, although cold, is not a death sentence for many roses. None of mine require any special protection for temps down to minus 20 F. But then I've planted roses suited for my area, realizing any others may be expensive annuals.
Plants in an area with an average winter low of 38F, experiencing temps of 7F, will have severe damage and I'm really sorry for your losses.
Should we blame it on climate change?

I've never done winter protection apart from a little heaped up soil on tender HT's. I'm resigned to winter losses after our last winter and don't care very much. But a friend wraps her climbers in fleece blankets, not horticultural fleece, but coloured and patterned picnic blankets she gets cheaply at gas stations. I've never seen her garden in winter and don't think I'd want to!

I have had no need to give roses winter protection, but I do need to protect some small young citrus trees, and the methodology might transfer. I bought a roll of concrete reinforcing wire, cut pieces of it that would roll around into circles large enough to go around the trees (usually about 12' of wire), then I cut off the bottom rung of the wire which gives me 6" pieces of sturdy wire that will push down into the ground. And then around that frame I put some of that light white fabric that the sell at the nursery for -- ta da "frost protection". In my case I also ran a set of Christmas lights under the bottom and around the trees to add just the slightest bit of warmth, so I have some funny looking white short towers around the property, but....hopefully I will still have some citrus.

The concrete reinforcing wire has been my go-to material for lots of things: arbors, tomato cages, trellises. It is worth it's considerable weight in usefulness.

'experiencing very unusually cold weather' - you bet. Standardised Temperature references - Yeah, you are right, Karl, but the truth is, I am a dimwit when it comes to weather as, by and large, it is pretty temperate here. Even so, as far as losses go, it is generally a case of mea culpa - a mix of denial, misplaced optimism, prevarication and idling......I shall regard it as natural selection ensuring survival of the fittest The roses should be fine.