I also am a bike mechanic and we are taking in kids in "need" at a later point in our lives. Our 8 year old absolutely loved being dropped off at school in a sidecar. I set up sidecars for other folks so I always get to test ride them for a while and the kiddo refuses to be left out.
Not that I think they are a good idea but the hand held video games can while away lots of hours while traveling.
Years ago a friend built his own sidecar and carried his wife and 3 kids in it. The littlest was still in a car seat but he made a fully enclosed rig.
I have built several of my own sidecars from the ground up but unfortunately laws vary country to country. One of my funnest rigs was a Ural sidecar mounted on a japanese shaft drive with lots of power.
Either put a reduced trail front end on or install a new set of triple clamps to reduce the steering effort. Then even a slight person can pilot a sidecar rig. My petite short wife took turns piloting our sidecar rig on a trip into mexico on bad roads.The Cycle Station - Trike Conversions, Parts, Accessories, Service
Since you are now parents and have a young one perhaps it is time to get a sidecar rig sooner rather than later.
Too bad you don't have the freedom as parents that we have in montana USA. We can legally home school our kids What a educational experience a trip such as you propose would be.

Helmets .. bicycle helmets are very light. They lack the hard outer shell but if your strapped inside the side car and not hitting hard stuff with your head it should be ok.
Entertainment .. I think the vibration would make a mounted screen hard to see .. better off in the hands?
Hydration - camel back for a kid? Don't know. Try it and see? Think a lot of it will be trying and seeing. What works for you will be interesting for others.

Good luck - take lots of photos!

Legals .. most people won't know .. most cops won't know .. take reasonable steps and you should be ok. Find out what is legal where you are and do that. Anywhere else plead ignorant tourist.

Wow it's been half a year, i let that thread slip a little bit. The wee 10 month old is now a very active and super smart 17 month old. We still don't own a ural or a sidecar, however my husband sold is 33 Scott and bought a 36 Standard 9 car Goes well with the 27 BSA in the garage

Thanks again for all your input.

We are actually allowed to home school here in Austria! It's just not very well known and not very common. All you need to do is do a test at the end of the school year and you can go on to the next grade.

It looks as if we are having a second one at some point in the near-ish future. And given that I - at least as of today - don't feel confident that I can ride a sidecar with one of my kids in it, we might just have to push the trip back. Or take a car :/

I do strongly believe though that a kid would learn so much more in a few months on the road than in a year in any classroom....

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'Normal' is just a setting on a washing machine.

I know this is a fairly mute discussion. However, I traveled all day trips and some camping trips with my younger boy in a sidecar. I had an EML sidecar, Tour T model, with a wind screen that wrapped around three sides of the outfit. He would fall asleep many times in the car, and I had no worries about him falling out. The wrap around wind screen was above the height of his head when he was sitting, and surrounded him on the front and both sides. I considered that feature of the car to be very important to my concern for his safety.

I think the Ural style tub with the open sides, or even cars with relatively low sides are more risky for kids. The rule I had was my boy always had to be sitting, but could look around and move around from side to side. With a car with lower sides, the rules are more difficult for a child to understand. There is no place for a kid to put his head when he's sleepy. In addition, since the pilot's first responsibility is to operate the outfit, he is not always/constantly monitoring the activities of an active youngster.

My boys do have fond memories about travel in that outfit, and I am glad I was able to share it with them. My girls were not so enamored, thinking it wasn't that cool at the time I had it.