Played some more and now I can pretty much escape consistently, for now the back entrance escape is the easiest in the slaughterhouse, because nobody is guarding it; you can almost just make beeline to it if you managed to get out of the basement without being chased, I'm sure this will start changing once family players realise this.
The other exits are a bit more difficult, but more tactically sound since they require going back into the basement, most family will keep searching topside for most of the time; if you are in a part with communication, you can really juke the family around by making sound somewhere else, having the others wait near the fuse exit, and then open that door so they can escape, when the door opens most family will make a beeline for it, so the one who opened the door is free to move to a different door topside.
I've also noticed how I keep getting the slaughterhouse day map, I've only played the house twice (night and day) and the gas station zero times; I wonder if this is on purpose, so you can actually learn maps (I'm pretty good at navigating the slaughterhouse now), or if it's just a bug..
Anyway my favourite victim is Ana, since she's very tanky and if you dump all her points in stealth, she can move around the map super quick; definitely don't forget to put your points in stealth/proficiency, those seem to be the best overall two stats for escaping, I feel the other stats are best for people in parties that can communicate to actually stun family members.
There's 3 maps though, I think with a day/night variant of each, but for some reason (as mentioned above), the others don't show up as often, for me at least.