I'm not really a nub, but I"ve never had this happen. I had made a starter for my Maibock a couple of weeks earlier, and let it sit in the fridge until I got ready to brew. It was a big starter, but it grew just fine and was only a couple of weeks old.
But I brewed last week and pitched the starter, and there was just no activity whatsoever for a full week. At first I thought it was just slow to start, then I thought it was extra slow because it was at 50 degrees. By the time I figured out it wasn't going to take off, I couldn't get more yeast for a couple of days.
But the wort stayed at 50 degrees the whole time, and was hopefully sanitary. I rack straight from a closed kettle into an almost closed and sanitized conical, so not much contact with the outside world.
What are the chances it's ok? Have people let wort sit, semi-chilled for a week and everything ends up fine?