If an event like this happened, we could easily maintain most of the trappings of civilization with a little effort and cooperation. So yeah, you're probably right.
GreyEyedGhost
There's good evidence humanity was down to the tens of thousands before, yet here we are. Source. I'm not saying we're guaranteed to get through it if it happened again, but a drop to half a billion people wouldn't even necessarily cause a significant reduction of genetic diversity.
If it's a one-generation thing, you will see some (or perhaps a lot of) social upheaval and a lot of artificial insemination/stud services, leading to a relatively brief dip in the population. Seriously, look up when Earth reached 1 billion people, and we're closing in on 9 billion now. If it's every generation, humanity will go extinct. Each fertile woman would have to have over 40 children to maintain population levels.
But his username checks out.
I'll let you in on something else. We spend as much taxes per capita on healthcare as America does.
Do a search for shower curtain rod clawfoot tub. You will find the correct solution to this problem.
I like Linux in general and I really like the idea of Linux, but this is one of my biggest gripes about Linux, and FOSS overall. They have all these instructions on how you can do this step or that task, but there are never examples that tie it together into a cohesive solution. This is fine if you have a good grasp of how everything works and just need pointers on specific command syntax or usage, but if you only have a general idea about what you want to do, there is nothing out there to give you an idea of how to get started.
Melted permafrost doesn't turn into valuable farmland. It will also cause higher CO2 emissions.
People always talk about looking for the silver linings, and here you are finding love in part because of a major disaster. Good for you!
I used to think there was nothing more stupid in zombie movies than uninfected humans just leaving each other alone and killing off the zombies. Why would you bother taking guns from other people when you have so many just lying around after 90% of the people died? If everyone just killed 10 zombies, the whole thing would be cleared up. I don't think that anymore.
And your rectum.
This is kind of like saying, "What if only America existed?" There would certainly be some disruption, but it wouldn't exactly be the end of civilization. Now, randomly distribute those people across the world, and it gets harder. But. The hypothetical plague didn't kill 95% of the population, it made them infertile. That gives you decades to prepare and recover if you're aware of the problem.