In reply to Dnwsmith:
I've had to pull out as my partner's got whooping cough
But if I were going I'd be taking a down jacket (for mid camp and to supplement sleeping bag). Sealskinz merino socks - even if there's no snow (which there almost certainly will be), there'll be icy wet ground. Full length sleeping mat (or balloon bed plus OMM mat from rucksack). And a reasonable sleeping bag (ie not my phd minimus).
I hadn't got as far as a decision about tent - but would probably go for something tiny as there's less air space to heat up - a larger more comfortable tent might end up being colder.