I've been hiking for the past 4 days in the area to the NW and SW of Tuolomne. Here's what I've seen.
I drove the length of Tioga Rd from Crane Flat. 5m NE of Crane Flat, the fire was visible about 5m N of the road, smoke billowing up from trees. However, the SW wind was pushing the smoke to the N of Tioga Rd, and no smoke was present anywhere along Tioga road, all the way to Tuolumne Meadows.
From Tuolumne, I hiked to Glen Aulin (5m WNW of Tuolumne Meadows), still no smoke present. In clear blue skies, I then started hiking W along the Tuolumne gorge, directly toward the fire. In 3 miles conditions had deteriorated dramatically (~1m visibility, uncomfortable breathing) so I turned around. The abrupt change in conditions in just 3m was striking.
After a day further NE at McCabe Lakes, I returned south through Glen Aulin. Conditions at Glen Aulin were still perfect (still air, clear blue skies, no hint of smoke), but the trail to the W through the gorge was now closed; a curtain of smoke could be seen a few miles W. I continued hiking S to Tenaya lake along the E edge of the new extent of the closed area, no smoke present. Crossed S of Tioga Rd to camp at Sunrise Lakes.
I picked up the JMT at Sunrise High Sierra Camp, and hiked N across Cathedral Pass to Tuolumne Meadows. At the moment, no hint of smoke is present anywhere along the JMT itself as it loops past Tuolumne Meadows.
At the moment, the SW wind is blowing the smoke well N of any part of the JMT as it passes close to Tuolumne Meadows. However, THE WIND IS FORECAST TO VEER TO THE NW ON 8/30. This could change things, and might blow smoke S of the Tioga Rd and into Tuolumne Meadows.
For those who want to play it completely safe in either direction, there's an obvious cut-out via Merced Lake and Vogelsang to the midpoint of Lyell Canyon. For SOBO hikers who want to try it, keep your eyes peeled as you go across Cathedral Pass: there is one place where you can see all the way to Tuolumne Meadows, and it should be obvious if there is a major smoke problem ahead.