As you indicated, making reservations during popular summer weekends, busy holidays, or peak tourism seasons is advantageous. There are times we reserve ahead if we want a specific site for a location we have visited before, other than that we wing it knowing where we are going will have some availability. As mentioned above, RvParky app on our smartphone has every type of RV listing available for the region we are currently located. Being 100% self-contained if we luck out we can overnight anywhere and still enjoy all the creature comforts our rig provides.