Obviously doesn’t totally solve the problem (or Airbnb’s stupidity), but getting most of the time back sure beats the heck out of waiting for Airbnb to do nothing and losing all of it.

This would probably help the guest out too since the large reduction in booking cost should result in Airbnb releasing a bunch of the guest’s money from whatever escrow account they keep it in before paying out.

If you really wanted to game the system, you could even try sending your guest a special offer of $1 for that one night. Then they could cancel their reservation after accepting the alteration request and the money they’re out should be negligible. I’d double check Airbnb’s fee policy before trying this, though, since I don’t know if they have any minimum fees that would make this not work.