You may have to open the window during winder if your heater keeps you at 22°C whilst temperatures in Scotland I assume are around the 10°C at the present time or at least they are here in Belgium.
My Aurantis were at room temp which was around 17.5°C and they were pretty happy, I moved them to my bedroom, which obviously has a warmer temp, and they didn't quite like that, and being my bedroom, I needed the warmth. They really do need a seasonal change of temperatures to thrive, even if you don't reach the bottom ends of temps they would get in their natural environment (sometimes 10-12°C in cold nights).