I live in the mountains of Vermont and bike 3 seasons a year on my trusty cyclocross bike. This year, I'd like to commute year round, through winter. My commute involves some steep, 10-18% climbs on dirt, gravel, and pavement with icy and/or unplowed snow. I've been debating about trying 2 different winter commuting setups:
Winterize my current cyclocross bike. This option has the obvious advantage in that it's cheap, since I already own the bike. I was thinking about swapping out my Schwalbe Racing Ralphs (700×33c) and going with the widest possible tires I can fit, probably 700x40 with studs.
Buy a fat bike. I've seen a lot of people talking about how much fun a fat bike is in the winter and how good they are for commuting. My main concern is the weight and climbing ability of these monsters on steep winter ascents/descents. Does this seem like a good option for my commute? I like this option because I could keep cycling through the winter, but this also involves buying a whole new bike.
Any opinions/experience is much appreciated. Thanks!
More specifics
My commute is 7 miles with ~2300 feet of elevation change. There are two short, but steep climbs with rolling hills interspersed throughout the rest of the ride. I'm mostly worried about the steep morning descents in bad weather and trying decide which bike option would give me the stability I need. Hauling a heavy fat bike up the hills is less of a concern, but climbing weight is still important to me.