Winter is coming (and Finland is amazing)

So with the crisp fall air, I'm getting nervous about the upcoming winter. Now in Ohio with two little babies, I wonder, how cold DOES it really get? I mean, I'm cold already, in September! I need  baby snowsuits, right? How thick? What if they don't come with booties? Does one (can one) buy booties and mittens separately? Will I be able to find two used suits at some garage sale in time? I saw this post on Ohdeedoh about the care package that expectant moms receive in Finland. How awesome is that?? Everything is so cute! And look at the cute snowsuit! I wouldn't be worrying like I am now!