The temperature of a house in winter when there is no heating will depend on several factors, including the outside temperature, insulation of the house, air leakage, and the presence of sunlight. In general, without any heating, the interior temperature will gradually approach the ambient (outside) temperature.
If the outside temperature is very cold, the interior temperature can drop significantly over time. However, it's important to note that the rate at which the temperature decreases will depend on factors such as insulation. Well-insulated houses will retain heat better and have slower temperature declines compared to poorly insulated ones.
Without any active heating, the interior temperature can vary greatly, and it's not possible to provide an exact value. It could range from slightly cooler than the outside temperature to potentially much colder, depending on the specific conditions and duration without heating.
To maintain a comfortable temperature in a house during winter, it is generally advisable to use appropriate heating systems or insulation methods to regulate and retain heat.