This is a great question and I’ve encountered this only a couple times in my 14 months with Airbnb. Each time was a different case and I handled each one slightly different. I have a firm cancellation policy.
In your case, if you think there’s a good chance of rebooking dates, I’d send a nice message saying you were sorry to see they were cancelling but if the dates get rebooked, you’d offer a refund. I’d offer the full refund but be sure you’re able to book the dates at the same rate.
I’m in the eclipse path and had a woman just cancel her reservation that fell during that time. Her email asking for a refund was the first time I didn’t believe the circumstances she stated. I sent her this reply:
"Dear ***, I was so sorry to read your message. First off, please accept my condolences for your Mom’s passing.
I’ll look at the calendar and see if opening the days is possible for re-booking. We have our own eclipse plans in place, which were planned around our Airbnb schedule.
If I can rebook another guest at a comparable rate, I’m happy to do that and then issue a refund to you. I’m not one to “double-dip”.
I’ll keep you posted on what transpires.
Sincerely, Heidi"
I haven’t received a reply from her yet but I did get a new booking, for better dates and more money. So I’ll refund her the full amount.
I agree with @KKC and I try to treat guests the way I’d want to be treated.
I had one guest cancel at the last minute and I didn’t want to have the days rebooked. It was a few hundred dollars. Once I got past my annoyance, I decided to just refund the whole amount. They sent me back a very kind email and I felt content with my decision.
Life isn’t black and white and I prefer to be flexible to each situation. I have the policy to fall back on, if need be, but there’s nothing unethical about giving a refund if I want to.