You can't camp above Illilouette Falls, and there are a lot of restricted areas throughout that whole lower drainage. You need to go to the link below and get your bearings- where the arrowheads end, beyond that is where it's okay to camp. Anything inside the lines is illegal, and if you're caught, you get cited and escorted out. Bad deal! If you want to stay closer to the Mono Meadows trailhead, there are some sites along Illilouette Creek around the junction with the Buena Vista trail. These sites may be crowded. Since you're coming down from Ottoway anyhow, better and more private sites are up by the Clark Fork. You'll pass so many on your hike down the trail along Illilouette Creek that your biggest problem finding one is deciding which one. Please think twice about whether you really need a fire in September.
https://www.nps.gov/yose/planyourvisit/ ... eID=292137Personally, I'll take Babcock Lake on the Fletcher Creek trail over Bernice Lake on Lewis Creek, but you need to make your route decision back at Tuolumne Pass.
I don't know how you're going to be with mileage and altitude, but don't take for granted how it's going to effect you...I've been doing this regularly for a long time, and I've hit the wall at Vogelsang more than once. Maybe throw an extra day on your permit beyond what you think you'll need, and if you can, try to arrive a couple days early and just hang out in camp, but make sure you schedule for after the last hurrah on Labor Day weekend...it'll be nuts.
If you're camping at Washburn, even though Triple Fork is beautiful and has plenty of sites, do try to get up to Lower Ottoway Lake that same day and spend your down time the next day there. You won't regret that decision. Sleep in.
The only real tweaks I might suggest is what you do after you pass Little Yosemite Valley and begin heading up the JMT. It's not so far mileage-wise, but it's steep down from Illilouette, and a long uphill slog to where you're allowed to camp on the JMT at Sunrise Creek (Make LYV nothing but a passing memory) I wouldn't try to push up and over Cloud's Rest that same day if you can help it. Instead, I would look for a site somewhere around the junction of the JMT and CR trails, then do CR the next day. You'll have a better site with plenty of water, and that's easier and more realistic for it. It's going to be September, so water sources are going to be more valuable opportunities, and that's just not going to come about going over CR. Certainly not for more than hydration purposes (btw- There MIGHT be a viable trailside spring on the way up, but your next certain water source is a creek about 2-ish+ miles down the other side from the summit...don't underestimate your water needs that morning, seriously!!!). That night, I would go ahead and make another shorter day of it and camp at one of the Sunrise Lakes. It's going to be so much nicer and rewarding in every way from almost all the alternatives closer to CR! From there, next day to camp at Upper Cathedral Lake. Last day, you'll be back at Tuolumne in plenty of time to have burgers for lunch.
I know what you mean about being stoked. We're so ready!! Since it's such a big and exciting trip for you, from so far away, trust me, take the time to go at a comfortable pace, get used to the altitude, and mostly, to spend the time it takes to be there and enjoy it.