I have what I call a proto-FAT bike, its got 44mm snowcat rims and weighs just 27 pounds. Could be a lot lighter with a couple upgrades [cough cough fork] Not as good as a full fat in deep snow, but faster than a full fat on packed snow and faster than a standard MTB in any snow condition. Mostly XT/XTR components too (older, but still). Got to sell it $600.
I have a car. I made a choice. I ride my bike.
If you haven't found one...keep trying Craigslist. People buying fatbikes just for the winter don't realize 1) how much harder winter riding is and 2) how much fun a fattie is in the summer. When I was looking for a bike 2 months ago there was a new one on CL every other day.