Just one add to BB's post. PLB's are a great rescue tool. I'll add to the list the InReach by Garmin. It allows two way communication in places where there is no cell service and can be used to summon help in an emergency. I have had one since Delorme first came out with them and have used them around the world and across the US and Canada. The only drawback compared to the PLB's is you need a subscription but the cost is minimal for the security you get.
As far as cold weather camping, we have camped in the dead of winter in our Northstar (somewhere between 5 and 15 below) and have found just a little preparation and common sense go a long way to having a comfortable and fun experience. Lots of good info in the OP's blog.