I booked our stay 1.5 years ago and it did not disappoint! It's one of the few Airbnbs that looked as great in real life as it does in the photos. We enjoyed the peace and quiet, loved seeing the goats and sheep, and were cozy by the fire. The hosts were very responsive without being intrusive. Perfect stay!
Only thing to be aware of, is traveling to Mayne Island requires some planning around the ferry schedule (2x per day, early morning or late evening) but it was easy to book and easy to bring your vehicle! This trip from Portland Oregon was a bit long (~7 hours factoring in drive, ferry, and Canadian border crossing) but it was worth it!