Purely speculation on my part but I predict the spillway will be a rolling pretty good come Monday...here is why I say that. Currently the lake is 677.62 which is 2.62 ft over summer pool. Winter pool is 668 so the lake is 9.62 ft over the target water level they want. We have not had any rain for the last 2-3 days but the lake is still on a slight rise. Per corps site it rose a little over 1/2 ft from Friday/Saturday. I drove over the tailwater today (saturday) and I was surprised to see very little current. I bet they open up the gate very soon...again pure speculation on my part. I don't know what's going on downstream towards the Ohio or Mississippi but if they're in good shape then they will start pulling Green ASAP.
As for fishing the tail water I have zero experience, however I have a coworker that often fishes there for walleye late winter and early spring. I ask him just the other day if he had been walleye fishing the Green tailwaters and his comment was "it's a little early but it won't be long before they start running". Based on some conversations we have had in the past I want to say he told me if the outflow was 800 or so cfs he had issues fishing the box and would go downstream and fish near the lower parking lot/bathroom area but if it was 1500 cfs or more then that was too much current to fish even if he went downstream a few hundred yards from the dam. I might be wrong on the outflow number he told me that was too much current but that is the number I think I recall him saying.
I am not trying to discourage you. I have not been on the water in a few weeks and I am getting the itch. If I wanted to go then I would go but I am only 5 miles from the lake so me wasting a trip is a lot different than you driving from Lexington.