After descending Tyndall, consider heading toward Rockwell Pass. The pass is an easy hike and allows you to drop down into Wright Lakes. from there you follow Wright Creek down toward the JMT. This saves miles and time. Rockwell pass is just west of Tyndall, actually it is the ridge from Tyndall. The pass is just a low saddle, class 2.
Camp at Wright Lakes.
This next suggestion requires you to feel comfortable with some cross country hiking. As you descend Wright Creek, maybe a half mile, off to your left, you will see trees and level hiking, just head through the trees and in about a mile, you come to the Wallace creek drainage and use trail. This saves about 2 plus miles.
Only do this if you feel comfortable in route finding and reading maps.
I take this route frequently to Wallace and Wales lake.
paul