Greenie, from what I've been reading, by those that would know, higher up is better. I would hike about an hour at a good pace up the trail above Elkmont and start fishing. I do think you can still catch them along the roads (in my experience). Fish the deep pools below a nice run of riffles. I would take off the dry and rig a double nymph/midge.
In the riffles might be good as well, but not in shallow riffles or in the sun in the heat of the day. Early morning as the sun is coming up might help as well, but those are guesses.