I am hoping to use United miles to acquire a single business class award reservation (one record locator) for travel from LIM to JNB (via GRU) for January or February 2018 (one part of a five week 'round the world trip). The specific through itinerary that the UA website is showing me is TA 917 connecting with SA 223. The scheduled connection time is 12 hours and 40 minutes during daylight hours. (TA stands for Trans American which is part of Avianca. SA is obviously South African Airways. Both are Star Alliance members. I will be Gold Premier-- at least-- when I make the trip, in case that effects the answers to any of my questions.)

Is there any safe way to make the transit connection at GRU which is described above (with baggage, either checked and/or carry-on) without having a Brazilian visa?

I want to avoid getting a Brazilian visa if humanly possible. I think I can live without checking baggage if I have to (but I would prefer to have the option to check baggage if possible). I normally travel with one regulation 45 inch total (22 inch maximum side) piece of luggage and one business backpack. The former often exceeds 10 kilos (22 pounds); the latter rarely does.

I have spoken to Avianca about both carry on and checked baggage, but the information I was given was either inconsistent with or not able to confirmed by what I read at their website. I have an inquiry in with South African but (a) I am still waiting for them to research the question (their response was far more professional in that they basically wouldn't tell me something just to say they had answered my question) and (b) they have zero control over what I can and can't do before I get to GRU. (United wouldn't even touch my questions but instantly referred me to the two operating carriers.) Therefore, my first question is specific:

(1) Is there anyone on this forum who has flown TransAmerican between Lima and Sao Paulo who can confirm what their business class carry-on policy is and how strictly it is enforced? (I had a situation once on an international flight on NZ where I had to keep reweighing one piece of checked luggage until it was a gram or two under the posted limit.)

(2) The Avianca agent said their maximum interline connecting time for through checked baggage at GRU was six hours. (I asked the question in terms of the specific twelve hour plus connection with SA described above but they were only able to give me a generic response.) Does anyone on this forum have any experience with the current maximum baggage connecting times for international to international transfers at GRU, especially if arriving on TA? (If I have to reclaim baggage at GRU, I will have to enter the country which means I will-- based on my best understanding-- have to have a visa which I really want to avoid getting.)

(3) Can anyone offer helpful but non-specific advice regarding their recent experiences making international to international transit connections at GRU?

(4) Have I made any obvious or stupid errors in my assumptions or questions shown above?

I wrote my local Brazilian consulate and they gave me a very prompt and seemingly clear but less than fully helpful response, which also didn't directly acknowlege the risks inherent in individual airlines' different checked baggage connection policies. (I had provided specific details regarding my two connecting flights including the twelve plus hour connecting time.)

Please consult with the airline that a new check in will not be required while in transit through Sao Paulo. If you need to leave the airport's transit area to check in again or for any other reason, you should apply for a tourist visa.

Thanks in advance for any help anyone on this forum can provide me in navigating the risks of a visa-less international transit at GRU. If and when I hear back from SA, if they provide any relevant additional information, I will update this thread accordingly.