I was on a Lodore trip that took out two weeks ago. Word from Flaming Gorge operators at the time was that flows of 1600-2600 would be sustained till September 30th. There is a daily fluctuation for power generation, but the highs and lows flatten out somewhat the farther downstream you are from the dam. This flow is great compared to the 850 cfs we have come to expect this time of year.
Firewood gathering is restricted to driftwood along the river below the confluence. I saw a lot of promising driftwood piles, but didn't stop to inspect them. Should be plenty of wood if you are willing to work for it. Some of our camps had stacks of firewood left over from the previous groups, too.