What I would do is attempt to book a few days earlier than you want for the first one. Then do the 2nd one the next day and the 3rd on the exact 11 month window.
Once you have all 3, then just go in and change the start date of the first 2 to the actual check in.
Because you have to do one at a time, you could lose out trying to do them all in one morning.
Also, when booking, only put in lead guest. Don’t worry about others. You can go back and modify to add all the guests later. It just saves time to ensure you get it booked!