I've a 2001 Corolla which has just passed the NCT. It doesn't appear to have any coolant loss issues or suffer from major oil usage (maybe a litre every 2,000 miles).
Any mist or fog on the windscreen clears quickly enough with the heater but jaysus it's cold enough inside the cabin though. These days the heater has to be switched on constantly otherwise t'would perish a Dane. I don't think there's a draught, I can't hear or feel one anyway.
I wouldn't have paid much heed to this only we picked up a 2000 saloon Corolla as a 2nd runaround last month. It's lovely and toasty warm in there when driving, no need to switch the heater on - just turn the heat lever to red - and everything also seems fine under the bonnet.
Any ideas why the first yoke feels like a fridge by comparison?