If I had all the time in the world I would not plan, but as it is I have a few weeks to go exactly where we want to go, so for me it is on the exact day of open reservations for the CG we are wanting I make it.
some places it is even hard to do it this way as more and more people are doing the same.
once we were going to hike up to Mount LeConte in the Smokies and stay at the lodge on top of the mountain, they have a few cabins, we set the days and then 4 of us started calling on the very minuite the reservation window opened for the year, it took us 2 hours of nonstop calling to get threw.......we got the days we wanted.
so yes I am just like the OP, and will do it this way untill we retire and have the time to just meander about.