Hokkaido itinerary in autumn

Greetings, everyone.

I'm planning a trip to Japan in autumn and I chose Hokkaido as my first stop for 4 days in hopes of being there in the right time for the autumn leaves.

Problem is I've been really confused when reading about the forecast for autumn foliage because every websites and traveler's accounts contradict each other. Some say it starts on september and lasts until mid october, others that Daisetsuzan starts and ends in september while in the rest of Hokkaido it lasts until the end of october...

So yeah, I have no idea what's going on anymore. Could you guys help me with that? I originally intended to visit Daisetsuzan and Shiretoko.

If you have any opinions about the rest of my itinerary, I also welcome them. My itinerary would be as follows:

October 12th to 14th - Arrive at Asahikawa. Visiting Daisetsuzan, on the last day leaving for Utoro by train and bus.
October 14th to 16th - Staying in Utoro to visit Shiretoko, then taking the plane from Nakashibetsu to Toyama and then the bus to Takayama.
October 17th to 19th - Staying in Takayama to visit Shirakawa-go, Kamikochi and Matsumoto. Then taking the train and bus to Koyasan.
October 19th to 20th - Staying one night in Koyasan, then leaving for Kyoto in the following night.
October 20th to 24th - In Kyoto, wanna catch the festivals in 22nd, leaving for Tokyo by train.
October 24th to 28th - Spending the last days in Tokyo before catching the plane back home.