6z was going well west at the end of its clown range. RGEM too, but maybe not as far west. All FWIW.
Regardless, I agree with RC about the GFS and not just because its a rainer IMBY now. It kept pulling the historic totals with the Feb system last winter, which was obviously wrong in the end. I mean I guess there's still a chance, but I wouldn't bet on it. December is not usually our (locally) prime time for widespread 12"+ amounts. It's usually January and February. Still, this whole thing has a major vibe to it because of the high wind and extreme cold aspect to it...even if the top amounts are only, let's say 12-14". Even areas that see 4-6" will have a wild ride with the cold/wind part.
If I had to pick the locales for the bigger snows right now, I'd go KC up through cyclone's/hawkeye's BY and then up thru WI. Subject to change of course...