Winter's probably easier to manage with a significant other because you can spend SO MUCH time together curled up on the couch watching movies or doing other things... My relationships are always more snuggly and lovey-dovey in winter. And why do you think so many babies are born in late summer/early fall? Because people have sex during the winter. Lots of sex. There's nothing else to do.
It is also much easier to ignore annoying things about someone when they are doubling as a heat source.
I have lived in Wisconsin for my entire life. We get awesome winters. I love:
Watching our dogs play in the snow
Drunken sledding
Using the weather as an excuse to stay in with a hot beverage
Brisk walks
Breaking out my favorite outerwear
Building snowpeople and other age-inappropriate activities
Most things I hate about winter have to do with transportation, like:
Being unable to bike places without nearly dying (I got studded tires for Christmas, we'll see how they do)
Bad drivers
Trying to go uphill in slush with a standard transmission
When it's too snowy to run safely.
Losing my favorite outerwear (scarves are sneaky bastards).