Lambecc, a few thoughts on your itinerary:
Horseshoe Meadow campground is usually fairly empty during the weekdays. During a holiday week, possibly higher demand than normal but I doubt you'll get skunked. It's 30 minutes away from the Portal. Add another 30 minutes to gear up and futz around at the Portal. Arrange your getaway time from Horseshoe Meadow with this in mind.
You might be inclined to start later in the morning since you're only going to Trail Camp, but every time I've done that I've regretted it. You're in sun with a heavy pack, and it can be miserable in that canyon by 10:00 if it's a warm day.
If you're inclined to do 2 nights, why move on day 2 at all? You'll be tired from the summit trip - packing up, moving 3 miles and setting up camp again (just to pack up again the next morning) won't be any fun. Stay at TC and enjoy the satisfaction of what you just did, and cut out a camp set-up and break-down. Or better yet, avoid the TC ghetto altogether and camp on the Consultation Lake ledges. It's just 20 minutes below TC and infinitely more peaceful and beautiful. And the marmot problem is significantly less - a few pikas and mice are all I've ever seen. More info
here .
Summit day - leave camp by 6:00 or earlier. That should get you to the summit and then back off the crest before a storm can brew up.
Key areas are pretty well signed, so I don't think you'll be mistaking one lake or camp for another. The section between Mirror Lake and Consultation Lake causes problems for some, but usually on the descent - pay attention. The trail on the western side of the crest is obvious - most of the way it's a steep ridge to one side and 1500 feet down on the other - not much room for confusion. A good map is advised, however. And be sure you don't take the JMT trail at the junction (a few hundred yards from Trail Crest). Happens more than it should.
Do not park in the day-use area of the Portal for an overnighter. Cars are being ticketed this year. If the other lots are full (remote chance during the week), use the roadside parking - plenty of it.
I like your acclimation plan. Eat, drink, pace yourself, and you should be golden if the weather allows. Best of luck.
