As you might know, in Holland we cycle....... A LOT.
We got all diffrent child seats too. My youngest was getting to big for my front seat. And the Eldest not ready yet to cycle on 2 wheels herself.
I saw 2 other mothers with an extra saddle on there bikes.
So after some digging:
We tested it yesterday. I'm still able to cycle normal and my little one still sits comfortable.
Even my eldest tried, she also sat well and felt like a queen :)
Now I'm still able to cycle with my 2 girls. No hot cars in the summer, just slightly breeze - cycle trips.
:) :) :)