Put your hand on the radiator. is it hot? even if your water pump was bust if the thermostat was actually opening then thermal conduction would heat up the radiator to be warmer then the -20F temps. You should also be able to have the car running and squeeze the feed tube from the motor to the radiator and you should be able to "feel" if their is water pressure or flow.
A water pump has fairly small vains/fins for the water circulation. Its also on the shaft that the pulley is on. usually the bearing will fail and will leak at the bearing. Dont know of anyone having the propellers on the pump brake and all at once.
Pull the thermostat and put is in warm water and get it up to just about to boil and see if it opens up or not.
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)