Sure but even at 32 km up it's still ~300 m/s, only about 15% less than the speed of sound at sea level. Let's say that by the time our hypothetical paper airplane start noticing drag the speed of sound is all the way down to 100 m/s. Hypersonic is mach 5+, so this implies speeds of at least 500 m/s.

Most paper airplanes I ever built would not stand up to 500 m/s airspeeds, I can tell you.