Dave,
I have driven from Oregon to SW Missouri in the winter quite a few times, I've always just taken I84 into Utah, then I80 from Utah to Iowa, then drop down to Mo. I have always found the worst driving to be in Mo. (Ice storms) The interstates have always been well maintained and travel hasn't been a problem.
Don

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> On Nov 9, 2014, at 1:25 PM, Dave Mcneely <mcneely4@COX.NET> wrote:
> 
> I may need to drive to Spokane, Washington from Edmond, Oklahoma in December, maybe late December.  I have been trying to work out the safest (meaning least likely to encounter serious winter weather) route.  I may have settled on driving a long way  around route involving taking I-40 to California, then up I-5 to Portland, then from there back NE to Spokane.  Or even dropping further south to hit I-10 and I-8 to get into California.
> 
> These are likely to involve at least 5 days of driving,  more if I do hit winter weather on I-40 (quite possible anywhere along that route until dropping off the plateau at Kingman, AZ) or even on I-20 in Texas.
> 
> Anyone have anything to suggest, including taking my chances through the plains and mountains rather than one of the these long way around routes?
> 
> Of course we would be winter prepped, with proper tires, emergency gear, food and prepared for multi-day stops if necessary.
> 
> My apologies, but this drive will not involve my camper, which has already been moved to Spokane, but rather my Prius.
> 
> Thanks, Dave McNeely