I've not read the full thread but I dont think you mentioned previously about 3am parties. That is different to household noise like doors slamming.
As I've said we have been unlucky with neighbours in the past and currently I've been wearing earplugs since moving to this current house as older neighbours go to bed at 1am and there slamming of drawers and opening sliding wardrobes wakes me up. Husband is able to sleep through it though.
Even the other night the washing machine was finishing up at 11.40pm. Theyve had all day but like I say they seem to come to life about 8pm, every single night, hardly hear a peep during the day. Its very difficult when buildings dont have good noise insulation, I do sympathise.
The facts are you are there just now, you can't move tomorrow.
Them waking your kids up is annoying you. How many times have your kids actually woken though?
Can you give your kids the rooms furthest away from them and off the party walls?
Can you play bedtime music on an alexa or other device in their rooms?
During the day so you are not so vigilant for noise can you pop a few alexas around your house and play music volume 1 with the everywhere group command, "Alexa volume 1 on the everywhere group", then "Alexa play my favourite songs on the everywhere group", just to take the edge off a bit.
Unfortunately it really is a rubbish situation but you need to be careful not to make it worse.
In the past before kids, if parties went on until 3am, I put "Foo Fighters - the pretender", on full blast from early 7/8am, for about an hour and then switched off. A warning shot if you will. And had it on repeat. Not that that is helpful to your current situation with kids I know.