With winter coming...

This will be our first winter needing to worry about a coat, etc... last year was nice with the infant carrier and just throwing a blanket over her and having a carrier cover (and honestly not going many places). I’m a FTM and have no clue how to deal with keeping her warm transferring her from her seat in to the sitters daily. Since she can’t wear a coat in her seat, what do we do? Do I just unstrap her and throw a coat on her with the car door open and rush inside? Sounds like a dumb question, but I’m clueless on what the quickest and warmest option is.