How do you help elderly parent(s) cope during cold weather?

Well, I wasn’t able to get my Mom(81) to her doctor appointment again because she said she was too cold. I left a message with her doctor to call me as she may end up in the hospital again for dehydration. She sits in her recliner under the electric blanket I got her recently and doesn’t move, just sleeps all day and wakes weak and disoriented. She doesn’t drink much to avoid having to use the bathroom and she doesn’t eat until mostly when I bring her food. So she continues to lose weight and dry out each day. She also needs to be diligent in taking her meds, including depression medications. I’m not sure what else to do. I prepare her meals and get all her groceries/necessities and drinks. But I just can’t get her to get up, eat and drink on her own. That’s the issue now that it's ‘too cold’. I agree it is cold, but the furnace is on and I told her to turn it up. The bill is not the problem. So I warned her that if she doesn’t try to drink or eat during the day, her doctor will enforce in-home care, which she is absolutely against. I will be working full-time again in March 2020, thanks to finally getting hired, so I’ll have limited ability to help her full-time. Does anyone else have this dilemma with their elderly parent(s).