Wuksachi will not be crowded - it's only the campgrounds!
You won't notice crowds (except at General Sherman tree and in the last remaining pool at Lodgepole). However, judging by what we just saw, it's still going to be relatively green and lovely around the meadows, and it will be quiet everywhere. Many of the campground people just stay in their campgrounds (can't say I blame them, it's very relaxing and there's lots of wildlife).
Wuksachi is wonderful because it has its own trails over to the Lodgepole area, through pine forests, and it is very close to the Big Trees. For some reason, everyone gloms around the General Sherman tree, but when we hiked to Crescent Meadow, it felt just like the good old days - only a handful of families and the occasional set of backpackers there. Wonderful.
I wanted to do the Heather Lake trail this time, but we had our dogs with us. It is an amazing hike (truly, the vistas out on the Lodgepole Canyon are amazing) and Heather Lake is a great destination (you won't be shortchanging anything). We did check out the trail head at Wolverton meadows - there were maybe six cars, so again, not crowded. Heather Lake is absolutely worth it if you can get yourselves up there (it's the first part that's steep, then it's not so bad). It does lure you into wanting to go backpacking, though.
Have a great time! Let us know how it goes (I haven't eaten at Wuksachi for awhile, but last time we did, it was great - let us know how the menu is). We got breakfast stuff at the Lodgepole Store (they have coffee at their snack bar too if you decide to do breakfast/picnic stuff).
If you head out to Crescent Meadow before 9 a.m., you can skip taking the shuttle - but the shuttle is still a good way to see it (park across from the History Center, the parking lot there has a nice trail around the hill by Beetle Rock, and if you're like me, you'll enjoy just sitting on Beetle Rock and watching the butterflies, ground squirrels and lizards, it's the same granite as on Half Dome...but with way less than half the effort).
Moro Rock is also on the same shuttle as Crescent Meadow - and it hasn't been too crowded.
We saw only one bear, which is as it should be during the day. Zumwalt Meadows will still be beautiful (and the drive is spectacular). I'm guessing Tokopah Falls is very, very low (the creek itself is just barely moving - and that's because there was some rain about three weeks ago; by September, you may want to think of another hike, like Congress Trail or Redwood Canyon (there was virtually no one there, either).
So unless you are camping, you have no worries.