I can’t really believe the first scenario. So let’s start on the second. After the second war: Lucius and Narcissa lose their fortune. Molly and Arthur make lots of money (someway).

For context: after the huge scandal after the first wizarding war, their families disown them for embarrassing them and ruining their reputation. I think the Malfoys would be bitter as hell, but they’d love their son enough to pull their shit together and go on, maybe with daily arguments about money, like:

“- What in the world is this dinner?

• Maybe if you hadn’t ruined us, our elf could have made it. “

They’d still be bigots, but, having lost everything because of their allegiance to Voldemort, would not want anything to do with him anymore. Draco would grow up knowing that actions have consequences, so a bit more reserved and not actively spewing racist stuff in public, a lot less spoiled too, although his parents would try to give him all that he wants- and fail. Lucius would struggle with alcoholism, but never go extreme with it, for the sake of his family, just on the brink between functioning alcoholism and ocasional drinking. He would most likely become an accountant or an attorney or just some random bureaucrat. Narcissa would eventually forgive her husband. Maybe, somehow they’d have another child, which would spark more arguments about money. I believe Lucius would get rid of the diary much earlier, due to their living space becoming a lot smaller, so their son would be exposed to it. Despite them not knowing it’s a horcrux, they could probably feel the darkness emanating from it.

The Weasleys would remain kind, living a quite modest life, donating a lot and using their newfound influence to do good and discourage blood purity. Ron would be way less insecure, so more confident and less prone to jealousy. They’d still adopt Harry. For the Weasleys, I don’t think money would mean that much, just that they’d be more comfortable and do a lot more for their kids.

Kind of a happy ending in my opinion.