@Mike-And-Monica0
A "long term stay" always has the "lomg term stay cancellation policy" attached, overruling the default cancellation policy. It means when your guest cancels, the first 30 nights are not refunded.
You are not obliged to refund those 30 nights nights, but it is up to you if you want to provide some more or a full refund, especilally if you are able to rebook the nights full or partial.
Do not feel "paining into the corner with guild".
Guests have the oppertunity to get Travel Inssurance when making a reservation, which would probably compensate the loss.