I LOVE LOVE LOVE my Shimano Nexus 3spd for my 5 mile round-trip commute. Given you've been OK with a two speed, you'll love it, too.
I'll see your Vermont, and raise you mid-Michigan.The coldest I've ridden was -8 F, and I'm not ashamed to say I took the bus home that day, and the day after that.. but my hub shifted just fine, thank you.
The comment about oil vs. grease may be valid if it gets colder, I don't know.
If you can, get one with a drum brake, too. I'm using V brakes and they are feeling pretty sorry for themselves.
My winter bike is an H400 Cannondale with [of course] vertical dropouts. That required some math and some help from the internet to get the right cog in back and chainwheel in front.
"Half links" also help for the chain. If your bike has horizontal fork ends, you're golden without gymnastics.
I've ridden my snow bike December through March since 2008. Not every day, but maybe half the time.
The hub is about the only thing that isn't rusted, damaged, or otherwise messed up. These things are impervious. The wide gear range helps when the snow gets heavy and deep.
Best of luck !
cheers -mathias