Gore canyon is just about gauranteed to be running labor day weekend. Exact flow is hard to predict, but water supplies in upstream reservoirs are good, I'd guess med/low to med flows at that time. Last year we were treated with 1300-1500 cfs flows around labor day.
Bailey is anyones guess. I looked though the data earlier this morning and 2005 was the last year we had boatable releases in the first week of september. They seem to be turning the water too low by the end of august. Combined with the fact that other Denver water sources are pretty full, I would not bank on bailey running. Check the gauge to see though!
Have a good trip.