VRBO Instant Booking Cancelation?

[Frank Kosiba]

We recently enabled Instant Booking on VRBO for a seasonal vacation property. The rates are $2500/week peak summer, and go down to $225/night off season with a 3 day min. 

We received a couple random weekends, which is good. 

Yesterday, we received a 3 day instant booking in October. Today, we had a couple who we've been talking to about a long term stay ask us if they could stay mid Sep-Dec which conflicts with the instant booking. Our preference would be to have the long term Sep-Dec renters. 

VRBO says we have 3 days to cancel. Website quoted below. Thoughts on canceling the 3 day booking in October so that we may book the long term renter? Would we get ranked lower, or receive a 'bad mark' somehow?

"Can I cancel an Instant Booking reservation?
Yes, you can cancel an instant booking reservation if the traveler does not meet your stated House Rules, Policies, or Terms and Conditions. If you need to cancel the booking for one of these reasons, do so right away. However, if a traveler meets all your house rules, then the reservation is confirmed and should only be cancelled if the traveler requests cancellation and you agree."

Thank you in advance, 

Frank