What?

Why the fuck are you spending so much of your free time thinking about rape?

LOL what? you choose the by far riskier of the two options, because... the other option is also "risky"?

and if you're a woman, at least some dude will come protect you, and while there are women rapists aplenty, there will be no woman on the planet willing to come save a man from being raped?

wtf is wrong with you?

I would certainly rather be the last man. In the other scenario the human race is going to rest on your ability to get pregnant and have daughters who need to have kids with as diverse a population of men as possible as will you. Or human civilization goes extinct. You basically have the same thing as a man but you don't need to be infertile for a year while you bear a child. It will be possible to possibly get a 100 babies started in a year although that is sorta iffy. Regardless you should be able to have a fair amount of sons that can impregnate some of the current younger women when they come of age and you might have a diverse enough pool to keep the species going. Its 100% a no brainer on which situation is better.

While sexual assault by men against women is one of the few unforgivable sins in our culture, with huge prison sentences

What kind of mystical country are you referring to here?

the situations you're describing are all part of patriarchy. women didn't make those laws, men make up an overwhelming majority of today's governments and when those laws were first made, women likely weren't allowed to vote, let alone form any part of government.

women didn't create these media tropes either, the narrative of "men big and strong and always ready for sex, women small and weak and can't possibly harm men" is a patriarchal one.

patriarchy is a horrible construct that seriously harms everyone living under it, not any particular group of people.

Counterpoint to either option: would you rather be the brother of the only woman left on Earth or the sister of the only man?

It’s the same scenario, you’re never getting straight sex again and now you have to protect your sibling against the rest of the world. Because who else will?