I'm actually going to try and contribute to the forums. This OP will be made into a guide for surviving the cold, icy touches of the poles! Please help and provide usefull info, and I'll add it in this post. As with the new farming system-You have to irrigate to farm. In freezing areas, water is always ice-Therefore, no water to irrigate with, therefore no food, therefore no booze as you need plants to brew. Anyway, post your tips, hints and tricks!
1. Embark with an aquifer. Aquifers are easy to breach as, if exposed to the surface, water that leaks out will freeze, allowing you to just dig past it. Then you can use that same aquifer to provide water for your underground farms.
2. Dig in fast, even if you don't have an aquifer, breaching the caverns is a simple staircase, feeding your dwarves is just as easy afterwards.
Avoid evil tundras and taigas, werewolves are guaranteed to charge right down your entryway and murder anything and everything.
Bring your own wood. Bring many many barrels and hundreds of units of food and beer. Forget your anvils and metalworking equipment, miners and farmers are your most important workers here, any you may want to bring a couple extra.
Mechanics should be brought and trained up to create a pump stack and waterwheels if you want a fortress near the fortress and want to supply water.
Don't go outside, if you set the minimum temperature low enough your dwarves, and definitely your animals, will freeze to death quickly.