I did the Via Grischuna mid of September 22, and found it really amazing and great. Totally recommendable. I had to skip the first stage due to a lot of snow and poor visibility and found it too risky being solo. However, I could easily go to the Dürrboden by public transport and instead did a return run from there. This is an overall asset of the tour, that you could skip a stage and still get to your next destination with public transport in little time. Gasthaus Spinas was booked out and I could not stay there, but you can take the train from Spinas and go to Samedan or Bever (via Samedan) instead and stay at a hotel there. Bever would also be reachable by foot, extending stage 3 (and 4 the next day) by ~4km. While the scenery was stunning all along the way, it was definitely the sight of Piz Ot behind Val Bever after passing Fuorcla Crap Alv which stoked me the most.
What an amazing experience! I love Graubunden and its special feel. I had the pleasure to join up with Dan, Janine, and Kim on their first run through, and I'm definitely the one who had the most fun (and least work!). I definitely plan on going back and doing a few of the stretches throughout the summer, it's also super convenient for day/weekends with access from the valley towns. I particularly loved the sections from Durrboden to Bergün and Spinas to Bivio. The gasthaus at Spinas was probably the best stay for me in regards to food and accommodations. Try to get there for a "Tyroler Abend"👌🏻.