In reply to Callumjnelson:
Ocotber is an odd time of year to be heading to Cham for PD/AD routes... It's more the time for significantly harder mixed routes. You might still get stuff done - the Cosmiques Arete goes in most conditions and snow ridge type routes would be ok but any rock high up is likely to be snowed up. Aiguilles Rouges rock routes would still be ok if the weather is decent and valley level rock would be fine but why go to Cham for that in the first place. So there might still be stuff to do but it will be much more of a struggle to find stuff in condition than in summer. Also colder, less daylight, crevasses not filled in but masked by fresh snow, fewer people around so fewer tracks to follow, only the Midi lift open...