Upvote:4
Both ways would probably be fine during October. Major snowfall can happen in October, but it's rare for it to close the highway for long. Your entire drive will be around 12 hours (I'm adding plenty of extra time since you're in an RV towing a car and you'll be driving alone).
You say that you have a few days to do this trip in, so I would just decide which way you're going as close to the departure time as possible. That way, you can watch the weather, and decide on a different route if snow is expected on one of the highways.
Assuming the weather is fine, I'd probably choose to take 80 because it's interstate freeway the entire time, which I'd feel more comfortable with (since I'm not usually driving an RV or towing a car).