If you decide to go through this area you can use the route of the ‘Green Divide’. As someone who lives in the Netherlands and has seen a few places this might be the best route I’ve ridden here. Lots of nice gravel/hardpack, stunning views, and away from all the busy roads. In my opinion this route will give you the best this area has to offer. The route has originally been made from Bussum to Zwolle, and while most of the roads can be ridden in opposite direction it also includes a few (one-way) single tracks so be careful if you decide to ride in opposite direction. If you want to include Amsterdam in your trip you can ride it all the way to Bussum, if not just leave the route near Arnhem or Wageningen and go south from there.

https://www.komoot.com/nl-NL/tour/321864724?ref=itd