Not a chance, if we're talking about the hypothetical actual prison.
Financial reasons:
1) That's an hourly wage of $23. I can make double that in a normal job.
2) I was already making $100k in my day job, so $200k a year isn't that big of an incentive. I've turned away from a more lucrative career track because it would have involved longer hours and more stress. Even that wouldn't have been actual prison.
3) I don't need a million dollars for FIRE.
4) It's not enough money to be a Bill Gates-level philanthropist.
5) I already have enough money.
Life reasons:
1) Just... no. The whole reason I care about FIRE is freedom! I like setting my own schedule, traveling to wherever I want, meeting new people, seeing new places. Sleeping in, going for long walks late at night, napping in the afternoon.
2) The psychological effects of prison do not end the moment you walk out the door. I don't want to have issues for the rest of my life because of this.
3) My social circle would be destroyed. I would have to start from scratch.
4) I am bad at both fighting and manipulating extreme power hierarchies.
5) As l&p pointed out: RESTRICTED INTERNET!
6) I would probably hate prison food.
Also, what's with all this, "maybe if I was young, single, and didn't have kids" nonsense? I'm young(ish), single, don't have kids, and I want to take advantage of that! I would miss out on so many things by going to prison. Do you think life isn't meaningful and worth experiencing unless you're married with children?
For the real situation: so the million dollars in 5 years is half market returns, that he will presumably get regardless of his job? That means he's only making around $100k? He could find something around that level in their home country that doesn't have a ton of stress, downsize the house, the kid activities, the restaurants, etc, work for 5 years and be done. Or work part-time. Or both of them could get part time jobs.
If I lived somewhere that made me miserable, I would not stay 5 years for any amount of money. I would much rather leave and rearrange my life to be more financially efficient in a place where I can be happy.
You shouldn't be convincing him to stay somewhere that he (and his family?) hate. You should be convincing him to spend less freaking money in a place they love!