Goslar-Bremen: to the west of Hanover is the slightly longer (10km) but less traffic-free alternative than the approach. A small gravel passage in Pattensen + the Neustadt am Rübenberge passage could be considered a downer. Especially the routes southwest of Hildesheim + past the Deister were fun!

I would like to do the tour in a similar form. But I won't be able to do it in one trip either, and am currently planning an overnight stay. I actually wanted to follow the suggested route on the way there. But after your travel report I will think about it again ;-)