I've never been in great shape, but I don't think there has been a big change in my conditioning over the past few months. I'm sure I've put on a few pounds with all the holiday meals, but nothing major. Cold has never really bothered me that much. I regularly ride when it's below freezing. But it was 55 degrees yesterday.
My wife has has both her knees replaced this year, so I know all too well about knee replacement. I made an appointment with the local bike fitter for early next month. Hopefully they can see something I can't.