In Nick's brain it is probably the kids fault that all this shit happened. He never gave an impression that the kids were much more than sources for interruptions and they just could not leave him alone doing much more important things like drinking and streaming and having orgies with wife and sex-friend.
So in his mind, having the kids removed and sent to grandparents is probably a great win for him.
His wife probably too since she too seemed more interested in drugged out orgies with Nick and April than to take care of the kids.
If it werent for the kids. None of this would have happened but now that the kids are gone Nick and Wife and April can go back to their old lifestyle without having to worry about the nagging kids coming and asking for food or other shit.
That is how Nicks brain works.
As for the lawsuit, they are first offenders and you really do not get to do time in this day and age for just "doing drugs in your own house" not even if you do a LOT of drugs.
So everything will be pleaded down and at worst a suspended sentence. He will not do a single day in big boy Prison. Thinking he will is just

More likely though si the grandparents take over the kids and they are removed permanently from the household and then the state simply drops all other charges. The state just wants the kids to be safe. The state doesn't really give a shit how much drugs or orgies he has in hos own house as long as only consenting adults are involved.
He has not learnt anything, he will not be punished and he will not change.
He will go deeper and deeper.
I think he will not stop until the state stops him because there is a dead body involved. Not before.
Now that he will not have to waste time on shit like "drive kids to soccer practise" and stuff, they can do drug fueled orgies 24/7 completely uninterrupted. I could well see him the wife and april even starting to stream on pornhub.
EDIT: Also, with the kids gone and so many extra rooms he can now re-purpose in his house. Nick, you got a brunette and a blonde. Get a red-head to move in into one of the spare rooms. You know you want it.