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The current conditions along any route have almost nothing to do with what you will encounter this weekend, and certainly nothing at all to do with what you will encounter on any subsequent weekend. What you need to do is to watch the weather between now and when you depart, particularly the day or two before you leave and the forecast for the day(s) you'll be on the road.

Very generally you are better off sticking to the Interstates which have shallower grades and wider curves than other highways, and receive priority when it comes to being assigned road crews to keep them open. Thus, even though it's perhaps a half hour longer (over a day and a half!), I would opt for I-90/I-82/I-84 through Kennewick and Boise to Idaho Falls, with only the last few miles on surface roads (US-26/ID-31/ID-33) to Driggs.

AZBuck