We made it shorter by using a lift down to Kals and bus to Lucknerhaus so we ware able to made full circle in 7 days while staying a day on Rudolfshütte because of a bad weather.
Then we were lucky to get a hitchhike to Fusch an der Großglocknerstraße.
Park your car at Kaprun Hochgebirgsstauseen (not allowed further)
Bus to Mooserboden
Exposed top part to Kempsenkopf (you can chosee an easier alternative track).