Just a heads up, PipersTravel, but we all have to remember that when traveling through states which have frequent winter snow, it's usually required to "carry the correct-sized chains IN the vehicle" whether needed or not. In Oregon specifically (we frequently travel through Oregon in the winter with the motorhome), you have what are called "snow zones" which are posted continuously through the winter, (24 hours/7 days) on designated roadways. This actually includes the Siskiyous on I-5 and the Blue Mountain area on I-84 both of which are MAJOR interstate throughways.
So, even though you may not need them, you are breaking the law and are subject to fines if you are not carrying them in the vehicle. As others have said, if you watch the weather forecasts on the internet, you can "time" your passage through these snow zones when the roads are clear. However, be aware that you are technically breaking the law if you do not have the correct sized chains in the coach. The chances of getting a ticket while traveling on a clear roadway are pretty slim unless you are pulled over for something else and the LEO wants to be nasty and writes you up for not having chains in the vehicle.
We never intentionally want to drive the snow zones while the chains required signs are posted or any snow is on the roadway, for that matter. We do what others have suggested and wait until we know the roads will be clear. However, we purchased a cheap pair of cable chains in the correct size to show the LEO just in case we are ever asked if we have them inside the vehicle. We DO NOT intend to use them ...in fact, we WILL NOT use them as there isn't enough clearance to comfortably use them anyway. But we carry them so we won't technically be breaking the law.
If you're towing your car, you theoretically need to show that the correct-sized chains are inside both vehicles in order to be legal from what we've been told by numerous LEOs. With that said, we traveled through the snow zones for several winters before we bought the cheap set of chains (for both vehicles). Again, as long as you aren't pulled over for something else --and even if you are-- the probability of them checking to see if you have chains in the vehicle are pretty remote, I'd guess.
Here are the Oregon chain rules; other western states have similar laws so just be aware:
TripCheck - Oregon Chain Law - ODOT
Again, this sign is posted all winter long, 24/7 in Oregon on I-5 @ Siskiyou Summit, Smith Hill, Stage Rd. and Sexton Mountain Pass. And on I-84 @ Troutdale past Hood River, Cabbage Hill, Deadman Pass, Ladd Canyon, and Durkee ...this is when the road is CLEAR:
The restriction is worded as follows:
Minimum Chain Restriction: Carry chains or traction tires regardless of conditions.
When chains are required, one of these signs will be posted:
Good luck and have a safe trip.