No - you don't have to change it every day for an 11 month walking reservation.
For ease, pretend today is Sept 1, 2024, and let's say your goal is to book a hot time of year (literally), August 20-27, 2025. Today, you can book at your home resort for a stay checking in Aug 1, 2025. So today, you book Aug 1-8, 2025 - the max allowed 7 nights. Your specific room is not available to anyone to stay in until the night of Aug 8, 2025 which can't be booked until Sept 8, 2024. Someone else can of course make a booking for a room for Aug 2-9, 2025 on Sept 2, 2024, but they won't be in your specific room as it isn't available. So this means that on Sept 7, 2024 you could amend your reservation by changing the start date to Aug 7, 2025 and moving the checkout date to Aug 14, 2025. Or, any time before Sept 8, 2024 you can amend your reservation. You can keep going till you reach your desired dates. Once booking opens on Sept 8, 2024, if you have not modified your original reservation, then yes, someone could come and scoop up the night of Aug 8, 2025 and onward and it could be in your specific room, effectively blocking you out. But as long as you modify sometime before Sept 8, 2024 (and continue doing so) then you will be blocking anyone else from taking your room until you have reached the dates you want.
This is why walking a reservation at the 7 month mark at a resort you don't own at is not guaranteed to work, because owners can always swoop in and grab dates that you as a non-owner can't access. Using the same date, Sept 1, 2024, assume you don't own at VGF but you want to eventually book for April 20-27, 2025. Today, you book April 1-8, 2025 with the intention of walking it forward. The problem for you is that at any time from today onward, a VGF owner can already book April 8, 2025 and more, because it is in their home resort booking window, so while you can still try the above steps, you may at some point be blocked.