Dad's habits have changed since it's gotten really cold here in Kentucky. Is this normal?

My dad has dementia and COPD. It's gotten colder here in Kentucky, he doesn't get out of bed or ask for anything to eat or drink or anything, This is the way he was when he first come to live with me back in March 2017, he's gotten much better health and habit wise, When he finally got to where he would eat, I'd fix him a big breakfast then he'd do a little snacking throughout the day. Any ways he's had lots habit changes thoughout, but now it's like he's reverting back. He doesn't get out of bed or ask for anything to eat or drink or anything, I have to go and ask him if he's ready for his coffee and to eat, take his med's? He responds with no I'm fine I don't want anything. Sometimes he changes his mind and sometimes he doesn't. This started right after Christmas and the weather change. Is this normal with Dementia and COPD?