"Really bad ice storms" are rare, and when they do occur it is usually in the Portland area where the cold air from the interior rushes through the Columbia Rive gorge. Driving up the freeway should be a non-event at any time of year. Keep an eye on Siskiyou Pass on the California-Oregon border for snow, however. www.tripcheck.com is a good resource plus there are webcams at the pass.
As a freeway hater, I would drive up the coast on US-101, which is close to sea level for most of its length, and is not subject to snow or ice storms except for those rare years when the news is full of warnings.Edited: 15 August 2017, 01:43
Thanks so much! We'll be driving with 3 dogs so the smoother the drive, the better!
If you do decide to use 101, be aware that you can get ice storms in northern California as well. My husband and I were "trapped" along that route just south of Eureka one winter. Fortunately we got the last available hotel room in whatever small town we were halted in by the highway patrol.
As someone who has traveled with cats across country twice, I recommend you research pet-friendly hotels in advance and have a list with you. Back then I used a book put out by AAA, but now there are several websites online that will offer info.
Hmmm. That's exactly what I'm afraid of. What month was that where you were stuck in NorCal?