Snowsuits - what to wear underneath?

[LaTristesse]

Sorry, I wasn't sure where best to post this... I want to get DS, 6.5 mo, a snowsuit for the winter but am a bit confused as to what he should wear underneath it. I obviously don't want him to get too hot (or cold!), and I know the car seat rules say they shouldn't wear padded stuff when strapped in, so do I just have him in a onesie or something light whilst in the car (will be cold going to and fro)?

(Sorry, I have a feeling I'm being a bit dim about this... )

Put a layer of usualy indoor clothes and maybe a fleece/cardigan over. When really cold dd had a fleece all in one tot go betweenn the two.

I just put indoor clothes on underneath (normal layers). You will probably need a beanie hat or similar under the hood as sometimes they can be a bit loose. Was the best thing I had for my December newborn!

I used it as a coat, so indoor clothes underneath. It does get really cold Jan/Feb so it's needed. Just keep an eye on them and remove say the top half when in a shoppong mall etc/unzip if in the car etc.