I did Westwater in November; was that last year?, and the water temp was cold, 41F; not close to icing though. Dec-Feb would probably have more chance of ice.
Looking at the past couple Novembers on the USGS gauge, I see flows from 3000 to 4000. Seems like plenty to float on to me.
On any of the USGS gauges, you click on the drop down near the top, choose Time-series: Daily Data, and it will show you a year graph.
Here is the one you want, USGS 09163500 COLORADO RIVER NEAR COLORADO-UTAH STATE LINE
Then you can change the date range for anything you want. Here is Nov 1 to Nov 30 2009, looks like Ruby-Horsethief stayed above 3000.
Change the 9s to 8s, and 2008 had somewhat more water:
You can look at all the past Novembers you want. Have fun, and stay warm!