Last year I started at Ötzerau for the trip home. The distance was 69 km. And it was also 17.08. 😉
From Zams home I had to do 85 km.
Do take a bike path is in general very fine because there are no cars and motorbikes.
On the other hand the distance is more and is more exhausting because more up and down. From the hotel in Zams to Lans by car Google.Maps shows 77 km.
LocusMap show climbs of 1.464 m and 1.425 m down. That’s absolutely wrong.
Komot shows ascents of 450 m and decents of 570 m. That sounds realistic.
The Inntal byke path is really fine. Mostly asphalted roads and the dirt roads are very well prepared.
This year I had no resistance coming home.