I find it hard to believe, that any of those first lv characters made it out of hell alive let alone with kids. Not sure of 5 edition works but the vast majority may not even have been considered 1st lv more like a Commoner. No they all would have been Massacred. I know a couple may have been adventurer types but yea, hell aint no place to be.
If all of the refugees are from Elturel, then yes... they did indeed escape hell.
"Baldur's Gate: Descent into Avernus" (basically a prequel campaign to BG 3) has multiple endings and in at least one of those the city of Elturel is returned to Toril after it was dragged into Avernus.
