Shin-etsu trail with a toddler

Hi everyone!

I am planning to visit Japan this October and we are a hiking family so I was looking on multi-day hikes we can do and stumbled upon Shin-etsu.

We will be doing it with our 3 year old son. My partner and I are both experienced hikers and we've already done quite a few multi-day hikes with our son as well so I'm not worried about the physical part of it. My son can walk parts and we can carry him when needed.

We are planning to do it with a tent and utilize the campgrounds whenever we can find one. And we want to do it by walking only - so no transport to accommodation and then back the next day to keep walking.

From my research I had a few questions:

1. How cold does it actually get in the area in October? I mean, we will have our warm gear, but some sources of information say it is fine and some say it is below freezing.

2. We are walking slower as a family since one of us has little feet and has to be carried so we average 15-17km per day. Occasionally, we can also do more if needed. By the locations of the camps I'm looking at 23-25km day between Akaike Pond and Mine Tozanguchi (sections 2 and 3). We have done these distances in the past but it takes us all day. Is it realistic to do it during daylight considering the sun goes down early? Is it doable with walking in the dark? Do I have other options (since I saw there are no accommodations in Wakui)?

3. I've been reading about animals on the trail and between the bears, wasps and snakes I'm kind of thrown off. Ideally we would not be wild camping at all, but do the official campsites really have less of a chance to encounter them?

4. How real is the wasp thing? I know how to avoid bears and snakes, but wasps are new to me. Especially with a child. Is there anything to do about it?

5. I couldn't find much information about food along the trail. As understand it I should be carrying food for 7 days (until Mori-Miyanohara Station) - Is there anything in between? Any supermarket that can make my backpack lighter?

6. Toilets. The camp sites have toilets and I've seen some other ones along the way. But since I'm traveling with a diaperless toddler I'm not exactly in control of when everyone needs to go. How does that work?

7. How true are the time estimations on the official sites? I see an average of less than 2.5km per hour. Is the terrain really that difficult? It's not what I see on the photos and the elevation maps I found do not offer a justification. I'm asking because we are usually slower than the estimations

8. Since all the hiking apps I know do not really function in Japan, is there a way to actually check the trail? I've tried YAMAP but I couldn't manage to find it.

9. How much ahead of time should I book the camp sites? How probable is it that they will be full at all? I've seen the lists of people that do the hikethrough yearly on their official website and it doesn't seem like a very frequented way of doing the trail...

Thank you for any information you might have!

If you know of an alternative 5-9 day hike (hikethrough) that is in that area I'm open to suggestions. I know about Kumano Kodo and Shikoku 88 so please do not suggest those :)