I wouldn't worry a whole bunch. There are several others from this board going up the same weekend as you. That's one of the reasons for the hiking calender. I would contact them, meet for a burger or breakfast at the portal and make your plans on how to approach the trail. It's a whole lot safer to go with several others, and also can be more fun. You can't beat new friends from the board. Doug Thompson says that there is "500' vertical melt a week now". With that in mind, I think you "should" be fine on a trip to Trail Camp, possibly testing the switchbacks a bit. You never know what conditions could be by then. It could be fairly clear and only snow or ice at the cables.
I'm going up a week later than you and my plans are to go to Trail Camp and see how the switchbacks look. I'm also going to check out the Mountaineer's Route up to Lower Boy Scout. I don't need a permit to go to Lower Boy Scout.
So, my advice is have a contingency plan for another hike if you like, but the snow level will be the same everywhere up there. If it's your goal to take the trail up Whitney, then go for it and stop when the trail becomes a bit iffy. Have fun, eat a burger, talk to all the friendly hikers up there, take lots of pics......and just enjoy the time on the mountain.

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