Well, I can only give the usual reply - it depends.
October can be good, can be bad.
Good if i has not snowed a lot yet and if one of the stable´fall periods come along, bad if the conditions are winterly already. In any case the crevasses will mostly be open (as open as they can be during a year).
- check in September where conditions might be good - www.basislager.ch
for Switzerland and Austria. There are a few French ones too.
- search for areas that are near weather borders, e.g. Reschen-Pass - north of it are the moist Austrian Alps, south of it the often drier Ortler Alps. The gives you flexibility. I assume also the region around Gran Paradiso or Chamonix and Courmayeur offer similar possibilities of choosing where to go depending where conditions are better.
- Avoid crevassed glaciers if you are not really experienced with them. This advice is valid the entire year of course, but even more in October after the first heavy snows. Pitz Palü e.g. I would avoid.
- have a 3000 m plan B. Often the Eastern part of the Eastern Alps (Marmolage, Triglav, Hochschober, etc) has much better weather then the regions further to the east. Can be worse too though.
In Europe the weather depends on the frontal zone moving up north, causing both bad weather from the NW or from local lows in Northern Italy. Hard to say. Stay flexible.
What else...experience with the weather of the alps!!! October storms WILL be nasty.