I (and a small group of fellow believers) run the Gorge a lot this time of year, all the way into November. And I've heard of a New Year's Day trip in there, but knuckle-dragging over ice bridges is not for me.
But yeah -- I think it's really fun at 300 to 400 cfs.
But there aren't that many that agree, it seems.
If you go down on the weekend in the next two or three weeks, you will probably run into someone if you wait. Go during the week and your odds aren't so good.
I'm going with a big group on Sunday - but we're going to be helping a bunch of newer boaters learn the run, so there will be scouting and general slowness, so you may not be interested.