Blanket over the engine, paraffin sump heater underneath...cardboard in front of the radiator.
That was my Ford 107E Prefect in 1970.
Open the bonnet, remove the blanket, if not freezing remove the card but if VERY cold leave the car and a good squirt of Bradex Ready Start into the air filter.
Assured start!!
Only real problem was that the car had no heater, it was an optional extra.
