Ive done a couple of big trips the last 2 years.
I do a bit of research on the areas to find best camp sites, things to do and places to visit, work out a rough route, but just go with the flow.
We like to travel when we feel like it, and change according to weather or tips from travellers you meet as you go.
It doesnt feel like a holiday to me if you have to keep to ridgid plans. Some of the best things weve done have been unplanned.
As long as your not OCD, otherwise you wont sleep at night.
Cheers Glen