So for a few days I've been looking at the UDOT traffic cam at the interestion of US 191 and UT 128 (where US 191 goes over the river). For the last week anyway, it seems traffic in general is lighter so the lines are much less. Not surprising as it is almost November. The week of Thanksgiving might get a little busy, but were definitely into the off season now. I'm guessing things will be OK until early March, when people get tired of being cooped up and head to Moab for some outdoor time.
As for when we were there, coming into Moab on UT 128 in the afternoon was definitely the best choice if coming from the east. One day we even debated turning around and heading up to the interstate and down UT 128 since we were camped on the river. Waited it out as we didn't want gasoline to be an issue.