In those circumstances I think I would have used extra heating in the dining room while entertaining family.
Fortunately the temperature here has remained fairly stable, 20.5°C downstairs, more upstairs, despite the bedroom thermostats reducing flow. The only times we have been cold are during storms, when the ach rockets. I need to double down on the airtightness.
I was relying on the Daikin figure for consumption but in early November it stopped reporting. Daikin can’t explain why, so I am having to rely on the smart meter, which doesn’t differentiate loads. I am also working through my Octopus credit and have left my DD at £1 per month until it reaches near zero.