I'm sure the thermostat was stuck, last I started and warmed the car it didn't overheat and I had heat in the passenger compartment. I bought one to replace it, have done them many times. But I believe my water pump is going too, even though it isn't leaking. I can now hear the typical bearing grinding sound, though not yet loud and only occasionally. And when I went to town for the thermostat the car's temp gauge kept going up and down, to just over halfway. The coolant level never dropped, so an air lock is unlikely. I haven't driven it too hot, and won't. I really wouldn't want the head gasket or block to become a problem too.
The water pump isn't a small job and isn't in stock here anyway. I need to get my son to and from school tomorrow for exams. Is there anything I can do to buy time, I bought a bottle of cooling system conditioner but not sure if it's actually worthwhile. Or do I have to just pull over and let it cool down. It's supposed to be bitterly cold, -38C with wind, until Friday. I don't have a garage or block heater. Any suggestions?