A year around Europe?

Hi all.

So I'll apologise for the vagueness of this post but... I'm not sure how to go about it otherwise!

A number of factors have resulted in me decided it would be a good idea travel Europe for a year and that I should do this by bicycle touring! My budget is around 600 EUR a month which I figure would be just about enough for camping and eating but toss in some wild camping and a bit of help Xing or couch surfing and this should be fine. Separate budget for emergencies, repairs and clothes.

Is it better to make a plan? I'm a project manager and everything in me is screaming "PLAN EVERY SECOND OF EVERY DAY" but the idea of just heading out and seeing where I end up sounds great.

I can explore (and already have for the most part) the capitals of Europe any time so I'd like this to take in lots of smaller places it wouldn't normally otherwise. The only thought in my head is north in summer south in winter...

How do you go about making sure you have a place to stay when you only know where you're going to be at 5pm at midday the same day? That's my only concern really at this point.

Just any general advice would be really appreciated.

Thanks!