Trip planning - is it too early to plan

Even though we have been on a number of large scale trips in the past, I still feel like a newbie to the planning and strategy procedure.  Every summer, for the past five years, we have known our departure date for our winter trip to the sunny southern climes.  It has always been fun, during the long, hazy days of summer to set myself in front of my computer, strategizing our next adventure.  
Once we have decided on a general destination, I can then take pleasure in investigating the possibilities of going to new places as well as deciding if we will be going back to any of our favorite past locations.
Because we are fully self-sufficient, ie. ample black water, drinking water and solar energy, we have the luxury of heading out to places further away than most might want to go.  Probably the first avenue of investigation will be for me to keep my ears open for clues from other travelers that have been to an interesting location, or to avidly read blogs and Facebook articles written by travelers that have been to the destinations that get my interest up.
So you may be wondering about the title of this blog.  The situation we are in right now is that we have decided to stay up north for the winter, just to remind us of the many reasons we decided years ago that we would rather be down south, out of the snow belt and away from the freezing temps that we would experience.  So it has been difficult to rein myself in this whole summer in order to not preplan for our next trip, which would be at least eighteen months away.  
Nonetheless, I have managed to find the odd spare minute or two, or three, or twenty to sit and think ahead to our next southerly escape, but I keep holding myself back considering how situations can change in a short period of eighteen months or so.
So I admit I am feeling frustrated, but I am also thinking about our next trip to the balmy California coastline starting in the winter of 2018