Wyatt wears a fleece coat under his winter coat on the way to our car, I then remove his winter coat and he sits in the car seat with just his fleece coat on (and usually a hat). He is still warm and he is SAFE!! When we get where we are going his coat goes back on before he goes outside. It really only takes an extra minute for his safety. He is great at getting the coat off and on and I think he would be uncomfortable being in a bulky coat in the straps anyway.
These are pictures I took to show how loose the straps would be if the coat was compressed down. When I put him in with his jacket on I put them as tight as I could. you can see how much extra space there is with the coat off. These pictures were all taken in a car seat on my kitchen floor. It was too cold to do all this outside so I used our spare seat. It needed to be cleaned anyway so it wasn't a bad thing to bring it in the house.
Wyatt in his car seat with just a long sleeve shirt on
This is something Wyatt would wear in the car. When I put him in the settings were still the same as above. It is a bit tighter but I didn't have to change the settings of the straps.
Wyatt in his winter coat. We had to loosen the straps a lot! I pulled the strap as tight as I could.
When we took the coat off.
Wyatt stuck his cups in between himself and the straps
I asked him if he could get out of the strap
Still doing it
He got his arms out and only took him a minute
This was just him posing and I thought it was cute so I added it :)