Hi,
I live in NH and drive a 2013 Leaf. Our climate (yours and mine) is not bad on the battery. Battery life will be much worse in a hot climate like Phoenix where 115F days are common. In Phoenix, people had bad battery capacity loss after one year! In NH, my battery loss after 3 years is perhaps 15% less than new.
There are some running threads here on used Leaf pricing. In general, it is much more economical to buy a used Leaf. You should be able to get a very good 2013 Leaf for approx. $13K, depending on options. But make sure that it isn't a southern Leaf that someone moved to the north. You can tell by using a cell phone app called Leaf Spy together with a $10 OBD bluetooth device. That's about the cheapest investment you can make in checking out a used car.
The 2013 Leaf has some features not found on earlier Leafs - heat pump for more efficient winter heat, heated seats, and better regen mode.
A new battery is approx. $6K, so even a used leaf for $13K plus a new battery is still cheaper than a new Leaf.
If you are used to 80 MPH highway driving, you will get a lot less range than 30 MPH city driving. I can drive more than 100 miles at 30MPH on one charge, but only ~60 miles at 70 MPH. For more details, see:
http://www.mynissanleaf.com/viewtopic.php?f=31&t=4295&p=122482
Running the heat will drop your range by roughly 15%, depending on how cold it is outside. Electric seats, heated steering wheel and headlights may sound significant, but they are not measurable energy consumption by comparison.
The Leaf is fairly heavy, so runs OK in snow. But if you put snow tires on it, you will see a hit in range. Ecopia tires give excellent range, and the range actually gets a bit better after 10K miles of driving because the tires break in.
If you have more questions, please continue to ask.
Bob