Nothing wrong with making plans, or gathering inspiration as I prefer to call it.
For the last few years I've always had a few tours "in the bag", so to speak, the basic information that I'll need if the time/opportunity presents itself.
At the moment, I can pull up info for a tour in Germany, two in Spain, one in Ireland and a few in Central and South America.
I set off to Spain to cycle to Santiago de Compostela with less than a week's notice because the donkey work was already in my kindle, similarly when another tour in Spain fell apart logistically at the last minute, I did a round trip from NL to Ireland instead.
And I always have ideas "plans" (ideas really) for overnight or weekend trips close to home, so when the stars align I can grab my gear and go.
Good luck!