Yes the cost is racking up very quickly, I have a smart meter and glance at the monitor daily, on my way up to bed. I mentally multiply the daily cost by 30 and get the heebie jeebies when I think of the monthly total. I, for one, am very grateful for the £500 this year. My house is well insulated, it is not an airless box so warmth does leave and cold does come in
I am managing a half a degree lower temperature here and there, particularly in the living room during the mornings, when I am often busy elsewhere in the house. My bedroom is maintaining a fraction just under 18, 18 is the recommended bedroom temperature for oldies