I sprouted a grocery-bought mango earlier this year and now it's about a foot tall with 6 sets of leaves. The 3G pot has been outside all this time with part-time shade in the latter part of the afternoon when the temperature was the hottest (90°s-100°s). It seems to be doing well w/ the 7th set of bronze color leaves peeking through this past week even as our day-time heat has rescinded and the nights have dipped into the 50°s.
I'm not sure what to do at this point with winter looming. There are choices: 1) put in the ground to winter outside, 2) keep it in the pot as is in the yard, or 3) take it indoor. I'm inland SoCA and our winter lows do dip into the low 30°s/high 20°s a couple of nights a year, but the duration is usually brief as even my in-ground frost sensitive plants (eg plumeria, moringa) have survived. However those were not young seedlings. I'm on a slope so pooled cold spots I don't think are too problematic. I've seen mango trees in other people's backyards but again those were fully grown trees. I'm curious as to which would give me the best odds for this seedling to survive.