Insulated drapes.

If they're out of alignment and don't close/seal properly, and you can't get them fixed before the cold moves in this year, get yourself a couple of boxes of Mortite or similar rope caulk and have at it.

If you dont use them, put up shrink film, they have it for sliding glass doors, I use it on my window's every year and I also put up insulated drapes as was already suggested.

What do you mean by "winterize"?????????????????????