Thank you GermanRoots, very useful stuff. I guess you suggest not to avoid driving around Luzern (others suggest here avoiding Zurich, which I will likely do). Your suggestions are very interesting and doable, would make the trip more interesting. I have a few questions if you have the time, would help me out a lot:
The default googlemaps route from Grindelwald to Martigny goes through Montreux and Chillon. Is this the route you took, or did you take a more southern route? How are the logistics of hopping in the train, and do you hop on it through the default route through Montreux? How long is the train ride?
When stopping at Chamonix and Courmauyeur, did you cross the tunnel twice back and forth? Or did you do (or is it better to do) Grindelwald-Martigny-Aosta-Courmauyeur-Chamonix-Annecy and although a bit longer, does not repeat a road?
How many days did you spend in Grindenwald? Is one night enough? Did you stay anywhere along that Grindelwald-Martigny-Aosta-Courmauyeur-Chamonix-Annecy route? I am thinking Martigny could be a good stop, as I would like to avoid a 6 hr driving day that route would take.
I will check Parkhotel Schoneigg.
I can't thank you enough.