More than likely what you are experiencing is a sticking thermostat. It is common on the 9-5's, especially when the temperatures start to drop. A check engine light may come on if the problem is not resolved soon. If the engine takes too long to warm up the engine management will store a fault code and illuminate the warning light.
Parts and labor is normally about $150 if they re-use the coolant (it has long life coolant which does not need to be changed).
If the outside temp is below 5 deg C, the a/c will not work (since it will not be able to make a change in the interior environment).
There is a chance the engine temp sensor wiring is chewed by a rodent- this would cause both symptoms too. If you see any rodent damage around the engine, I would have it repaired first. The rodents like the coolant temp sensor wires for some reason.
Let me know if I can assist any further.