1. Don't know how your child travels but for us, less is more. Our daughter (age 3) hates car travel

We are going to wander around Europe in September with a 3-year-old in tow. We are planning on starting in Prague, possibly going up to Berlin, then over to the Netherlands, and ending up in Brussels. We don't have a lot of time in each place but I'd love any recommendations on must-do things with our family. I'm debating on ditching all inclusive travel with islands vacations the side trip to Berlin and just renting a car and wandering through small towns in Germany on the way to the Netherlands. Any suggestions for small towns to visit on this path that still might have enough to entertain an adventurous couple and a toddler?
1. Don't know how your child travels but for us, less is more. Our daughter (age 3) hates car travel and more than 2 hrs in the car is a misery. all inclusive travel with islands vacations I'd be more tempted to pick one destination and do day trips, all inclusive travel with islands vacations or just enjoy the single destination, rather than taking a little one on a major road journey (and Prague to Brussels is a long way). But maybe your child is a great traveller and there's no cause for concern.
2. OTOH I love the particular pathway you've chosen, and there is a lot to keep busy on that trail. You might be interested in researching the German Fairy Tale Road, which traces destinations connected with German fairy tales (think Brothers Grimm). That might fire up the imagination of your child, if you can read him/her some of the stories connected with your destination.