My roses look hideous and need pruned, but would that stimulate lots of new growth that would end up getting frozen too soon?
Can you hang on a couple more weeks - I always do an autumn prune because my soil is stony and loose - a winter cutback helps prevent windrock. Once the leaves are changing colour and falling, the plant does not race into a new phase of regrowth. I should add that I am not very circumspect about pruning and mostly do it when I have secateurs to hand and I am irritated with various canes and clumps of growth. I often cut back a few canes now because I am starting the allotment clean-up - not a job I wish to leave until there are heaps of damply dying haulms, branches and leafage at a time when I am watching for fresh new spring growth. So yes, there are times when new growth gets hit by frosts but hey, this has never been a big reason not to snip away.
GF, if you prune now, won't you be cutting off the fall flush? There is probably not time left for latent buds to grow into blooming shoots. Light pruning won't hurt the plants, but severe pruning would force basal shoots that wouldn't survive winter and that would have wasted stored energy in growing out.
After a hard freeze stops growth and bloom, you can top overgrown plants, but don't cut as far down as you would in spring pruning, because (at least in my climate) cankers may develop at the pruning sites.
I never recommend fall pruning. The plants have stored energy in those canes and will need it going into winter and next spring. If something is really too long and waiving about in the wind you can take off some of it but I prefer to stake and tie the canes for winter instead. Next spring when they start to bud out the plant will tell you were it needs to be pruned down to. If you prune them down now you are still going to lose more to die back so by next spring you'll end up with nothing but stumps left.