How doable is taking the train from Garmisch to Innsbruck to Salzburg? We will be staying in Garmish (3 N) then Salzburg (3N) then onto Munich (3N). I did not necessarily want to go back to Munich to get to Salzburg. Would the route from Garmisch to Salzburg via Innsbruck be more scenic? I don't mind if it takes more time.