Honeycomb perfect fit blinds - insulation?

[applegingermint]

The bedrooms on the east facing rear of our house are very cold. Has anyone used homeycomb thermal Perfect Fit blinds to improve heat retention? My 3yo has been complaining it’s cold despite a radiator on max, a 13 tog duvet and fleecy winter pyjamas.

It’s a small double room if that helps.

https://www.blinds-2go.co.uk/blackout-pleated/52889/click2shade-blackout-pebble.html

Is the ceiling of the room insulated up to modern regs? That will make a huge difference and if definitely worth checking first.

We have thermal blinds but ours are roman and I think they make the most difference in the rooms where we have thick curtains too. So the curtains make the most difference and the the blinds top it up a bit. We have crap old windows though so with modern double glazing I am not sure if they would be worth the bother.