I don’t believe it
I hope my guess diagnosis is right, but if you turn the main oven on it neither gets hot or increases the household electricity consumption. I’ve guessed at the element.
It could be worse
It at least had the decency to not wait till Christmas Day to do this or do half the Christmas dinner then die. It also means I now have plans C and D in my head.
Plan D
Does anyone know how long it takes to BBQ a roast dinner? We are lucky that we have a BBQ wide enough you could cook with indirect heat in there. Also being the gadget nerd that I am I of course have a meat thermometer.