Condensation, heating and improved ventilation
Improved heating and ventilation coupled with specific action in relation to cold spots will usually result in a significant improvement in conditions. A modest but constant background heat is preferable to intermittent heating since this will help to maintain a higher average ambient temperature in the fabric of the building.
If you have central heating, set it to provide background warmth in ALL rooms including any unused rooms. Use the heating system on a regular balanced cycle with all radiators working in all rooms, especially during colder periods.
For those that do not have central heating, consider the installation of suitable thermostatically controlled heaters where necessary. However, do not use paraffin or bottle gas heaters for this purpose.
It is worth highlighting however, that simply heating the air is unlikely to be a satisfactory condensation solution, both in terms of cost and practicality. Unless there is sufficient background ventilation with efforts made to reduce excess moisture and rectify cold spots, heating is unlikely to resolve your condensation and mould issues.