I don't have a strict or moderate cancellation policy, but I believe others do. It sounds like you might want to use a strict policy. The strict policy refunds 50% of the rate up to 1 week before the reservation. At that point, no refund would be issued. (At least, that is my interpretation).
So if a guest cancels 8 days before their booking, you get 50% of the fee. I understand that this isn't maybe ideal, but hypothetically, you would be saving some money the week they are not their from the fact the house is not being used/unneccessary to have a cleaner that week, etc, and you still have the possibility of booking the place. Given that you have already received the 50% from the guest, you could offer that week at a steep discount and probably get someone in there to make up the difference?
If the guest cancels 7 days before the booking, you get 100% of their fee. Which, obviously, would more than cover the cost of not having someone in there that week.
If for some reason you don't want to use the strict policy on a case by case basis then I think you can adjust that through the resolution center at your discretion (suppose someone cancels 4 months in advance and you already have someone interested in that weekend, something like that).