Splitting up a pair of kittens at 6-8 weeks?

Hi everyone, recently I rescued a pair of kittens from a park. One looks to be the runt and is half the weight of the other, who is more obviously about 2 months old. I believe they are from the same litter.

I am only in this city for park of the summer though, and I'm leaving in about a week. I've been trying to find adopters for both the last few days, but it's really difficult. So far I have only had one person respond, who has a cat at home already, and they can only take one.

Is this okay to do? I'd make sure the second kitten goes to someone who also has a cat, so that they aren't alone. But I feel awful about breaking them up. They sleep with each other, fight, and clean each other a lot.

On the other hand, I only have seven days to find someone. There are a lot of cats in this country (China), so as far as I am aware I can't really just surrender them to a humane society and ask they take care of it.

Please let me know what you think.