A few things.

Switzerland is so open that you can find plenty of space to ride out in the country-side.

I tried keeping up cycling training in Brisbane and it's next to impossible. Switzerland is much better in that regard, so I don't think you will have much trouble with that.

As for the cold, get yourself some pull on sleeves and some leggings, once you are riding they are more than enough, also a light spray jacket for the colder days. i'm not sure how your wheels will go there, you may need to alter and not use slicks in the winter. During summer its between 12-35 degrees celcius, and the sun goes down at 10pm. Perfect for those long afternoons of training 3 hours on your bike after work. It's not cold all year round there, it starts to get really badly cold around November and then up until about march or may it should start to get warmer depending on how long the season decides it will be.

I would also recommend some altitude training.
Run, and cycle at altitude. You will seriously give yourself an edge over all other triathletes as this is not something that they use for training (except for your world iron man champs)
If you can find a place at altitude where you can practice swimming legs also then another bonus. you will find the first few weeks of altitude training very hard. Don't push too hard when you commence this training, altitude training is something your body will take time to adapt to.

Good luck. I haven't done a tri for a looooong time now, I remember the 3 hour stints on my bike....not cool.

I am sure you could find a good cycle squad there to ride with, best bet is to ask around at the bike stores as usually most of the guys that work there will already ride and probably have some connections you can take advantage of.