[LakeCleElum]

I did that trip a year go. Spent a night in Dusseldorf, Bremen and then the edge of Poland on the way to Prague.....Nothing really remarkable about Northern Germany in my book. Fun bars and restaurants in any town along the Rhine; Dusseldorf was great for that.

With your time constrains, I'd say spend a night somewhere in Poland on the way. That would be more direct than some of the other places you mention. Have fun. Prague is a great city.