Where will they go from here?
Harry will go home, in one form or another. Whether he's physically in the UK or not, he will go back to the RF in some capacity. South Africa, maybe (if they'll have him) with his children visiting over the holidays, and that'll be it. Invictus isn't going to last, it's too mired in corruption (which is a shame, but inevitable). He will soul search, he will find some random faith to turn to to "heal", he will live remotely, he'll play polo occasionally. One day, he will reappear with teenaged/young adult children, looking aged and chastened, back in Westminster Abbey or some such. He won't talk to the press, he won't write any books. He'll give up because he doesn't know how to do anything without help and he won't ever trust anyone around him to help again, ever.
Meghan was raised to never give her milk away for free. She will do what she's always done: hustle. She'll never be what she aspires to be, but she will go to her grave looking for it. She's got two children with Harry, she'll be just fine for the rest of her life. She'll appear on a red carpet here, a gala there. She will get more and more plastic surgery to continue to look hot and desirable. She will post about good works. She will be forced to keep an otherwise low profile in return for child support from Harry, which is what will keep her designer gowns a couple of times a year. She'll be a real housewife looking down her nose at real housewives, touting her and her children's titles at every turn to assert her superiority.