It is always difficult to understand how someone else wants to live their lives. My late father died 200 miles away, and although I visited often, his flat was freezing (he had enough money, plus savings, to pay the bills !) I used to turn on the heating whilst I was staying there …….he said he wasn't cold, but the medical profession says this can be true as sometimes people with medical conditions do not seem to feel as cold as we do ….Me, so far I don't feel the cold either but I do put the heating on, have hot meals and an electric blanket for winter, warm drinks etc …..have you (hard as it is) discussed what could happen if she goes into hypothermia when she is alone …...and if she is able to, discuss what she wants as her funeral arrangements ….that might get her thinking ! (not macabre, we all should have these discussions, healthy, well, or not !) Best of luck. Oh yes, my brother also died last year in a freezing cold house ...again, he had a lot (and I do mean a lot) of savings, shares, etc etc so there was NO need for the house to be cold ...he was found alone in bed by the Police following a call from his friend who could not get an answer (I lived in another country, and he did not often call me ...always said he was too busy ! bless him) ….another consequence of the cold he died of pneumonia (never kept his hospital appointments despite me nagging him !) Good luck