Walking at 7 months can sometimes work. For example, I have seen in the past a chance it could work for Easter week or July 4 time, although not for the usually impossible to get rooms at 7 months out (e.g., AKV value studios or 2BRs).
What I have seen happen at Easter is that some rooms, like BLT lake view, may be open for all of Easter week up to about 7 months out from Good Friday, so if you start a walk 7 months out from Good Friday and want, e.g.,the Sun through Thur, you may get it, but if you wait until 7 months out from Easter Sunday to reserve, the room you want can be gone for some of those nights. Similarly, rooms for July 4 time may show as open 7 months out from about June 28 but then by 7 months out from June 30, July 3 and 4 are often gone, so if you start a walk with June 28, you may get what you want, but wait for June 30 or after and you will not.
Nevertherless, the time you want, F&W, has a much lower chance for a successful walk than time outside of the fall frenzy period.