You've checked availability that is showing online. Now you want an exception to what is showing. For that you need someone with inside access and the ability to override current inventory. For that, the property must be contacted, either directly or via HH. There are so many different rules that could be in play for booking rooms with minimum/maximum stays, room class availability, and capacity controls. I doubt we will ever see all that put into our hands.

Good luck on getting the dates you want.