Hey Bec,
Sorry for the late reply!
A good place to hear about regular meetups is the Aussie Meetup group. Brett, the guy who runs the group, has just started up regular monthly meets again: http://aussie.meetup.com/164/
As for places to live, that really depends on what you're looking for. I'd suggest that anywhere downtown or close to it would be good, so west end, downtown core, yaletown, gastown, kitsilano, south granville, most parts of East Vancouver etc etc.
If you're looking to meet folks, probably staying in a hostel for the first few nights would be a good place to start. I have various friends who stayed in places like Same Sun on Granville St and ended up making a bunch of friends - usually other Aussies here for the same thing.
Driving in winter is like asking how long is a piece of string. If you're on Number 1 and the weather is good, then it's just like summer. If you're on a back road and it's just snowed a shedload and you're in a Peel p50, then you got problems
Seriously though, black ice can be an issue, so take it easy, drive where others have driven before, and try and drive an an awd car if you can.
J