How does the Weber Spirit perform in Winter?

I was a gas grill skeptic. I lived in a small apartment and made awesome food with an electric stove and cast iron pan.

Then, around a month ago, I bought a house and a Weber Spirit. The flavorizers (which I thought were basically a hoax) are the greatest things ever.

I've grilled basically every night since then. The only issue is that I'm in the midwest and we have VERY cold winters. I'm wondering if the Spirit will still perform in extreme cold or whether I should have gone with a Genesis (or whether I should buy a Genesis in late Fall to prepare)? My understanding is that the Spirit might have trouble keeping its temp in the cold.

Also, before you say it: I am very confident that I will continue to grill in the winter. I know my limits, and this is not close.

Thanks!