posted before about a family celebration being held near Frankfurt. turns out it's in Rudesheim. have now booked return flights from Frankfurt for two weeks. now need to decide what to do with a nearly 5 and 3 year old.
saw something for a touring holiday following the Grimm brothers tales, or castles on the Rhine etc. planning to not travel too far, stay three, or max four different places over 12 nights and explore where we're based, be it river, forest, castle, other. heard it's wine region but maybe that's wishful thinking 
does this sound feasible? what's accommodation like in Germany for beginning of August - essential to book in advance? short term let's, hotels or apartments?
any advise much appreciated, thank you 