In reply to iamaclimber:
How much are you able/willing/planning on moving about? Public transport? Car? Camper van? Camping? Hostels? Depending on your options, it's difficult to suggest things in case they're not possible in terms of your ability to move around easily, certainly more so the further north you go...
Given transport and willingness to travel though:
Glencoe - Traverse of Buachaille Etive Mor, and a day in Lost Valley and Bidian nam Bian are both great outings.
Multiple options for great days out in the Grey Corries and Mamores ranges.
Base yourself in Glen Shiel for a few days, loads of great walks up that way.
North Skye and the Trotternish hills (less likely to get winter conditions mind you)
Applecross peninsula with walks on Beinn Bhan and the Glenc arron hills.
Torridon (Beinn Damph, Beinn Eighe, Beinn Alligin)
Make plans, look at maps, keep an eye on the SAIS site, keep an eye on here for what's happening in the hills, but above all, wait until nearer the time, see what conditions are doing, check the forecast (again) and only then make a decision!!!
Also, check out www.walkhighlands.co.uk for some ideas and inspiration
Good luck, a month of adventures sounds like good times on their way.
Cheers,
Gordon