Bariloche is to crowded for me.
I suggest you start from San Martín de los Andes. You take a bus until the entrance of the National Park at Lolog lake. There begins a single track that takes you into the mountains for 3 days. You must to ask for permission to the guardaparque. If you don´t arrive at the other side he is going to go for you by horse.
The first day is hard, up and down the mountains. At sunset you arrive to the other side of Lolog lake. Just before arriving you have to cross a river, ask the guardaparque where should you cross it. It is wide and might be dangerous only if you are stupid. Don´t camp close to the river, this is where Pumas hunt at night. You can see many prints during the morning.
You will find a small house, don´t use it. To camp close to the lake is better.
The second day is mild. You arrive to another shelter. Don´t use it, there are mice at shelters.
The river you have to cross just after the second shelter is dangerous, so you have to cross is during morning. It is like a Y. Avoid crossing close to the place where the two streams becomes one. This waters are tricky, so be very careful. I fall there.
The 3er day is hard, half day up until you reach the escorial and the vulcan. Then the sight is great. After that is easy. You can camp at Laguna Verde. 1000 mts from there you can buy food.
You are going to cross just a few people, probably guides. They will be nasty because they want this place just for them.
Then you will be at Currue grande and Currue Chico lakes, it is not crowded at all because the road is very bad.
If you walk 15 kilometers to Chile, you will find Lahuen Co Hot spring waters. You will love them. They were biulding an hotel there, but you should talk with the guardaparques because the whole place is full of natural springs, but some of them are simply too hot.
They have a camping close to las termas, probably closed.
5 kilometers to Chile, there starts another single track called "Viejo aguila´s". You are going to cross through the cold jungle to La Union, the point where Huechulafquen and Paymun Lake united. It takes 1 day. There is also a detour that goes around Paymu lake, I don´t know if this is open.
Once you are on the other side, take a bus to Junin de los Andes ASAP, the campings there sucks. It´s full of people who just drink cheap wine, plays the guitar the whole night and sleep the whole day.
You can chose to do not cross the Union and to go back to Junin following the Huechulafquen Lake, this is the best option.
The water at Huechulafquen east coast is not drinkable. There are water nails that will pass you intestinal parasites.
Once in Junin you have 2 options. You can go to Tromen Lake, there is no bus and there are 60 kilometers of sandy route. At tromen you can hike the Lanin Vulcan until the 1st shelter without proper climbing gear.
The other option is to take a bus to San Martin de los Andes. (Don´t spend the night in Junin, it is too expensive).
Once in San Martin de los Andes, you take a colectivo to the other side of the lake. Once you arrive there, there is a camping which is tricky because it is going to be raining. You should not wait until it stops because this is the wettest place in the country. So just walk to the termas, I can´t remember the name, you just walk to the next guardaparques. It´s like 15 kilometers by the road. Then you cross a river and you have a free camping. The places around are full of wild mint for your tea.
Then you have a 2 hours path that takes you to a hot water stream that is a cascade that falls downs the mountain in a place like a V. There are many pools where you can enjoy the hot water. The higher you go the hotter the water is. This is a great place to rest a couple of days.
I wrote a article about this about 12 years ago, I should track it...
I was doing this "tour" every 3 or 4 years for the last 17.
Regards