City on Fire wasn't a TV movie - It's a Canadian theatrical production (one surefire way of telling it's not a TV movie is that Ava Gardner drops an 'F' bomb in it!
). It's the sort of the film though that was 'always on' during the 80s; although I recall ITV showed it last round about the mid-90s, post-10 o clock news and I don't think it's been shown on UK TV since.
Re the mystery film about the mad surrogate mummy, I think you might be referring to the 1982 'video nasty' Nightmare Maker, also known as Night Warning and a couple of other titles. Despite it having fallen foul of the UK censors at one time, people often refer to it as having a TV movie-like quality in reviews. Here's the video cover
Yes!!!! That looks like it. Thanks. I'm gonna have to try and track it down to watch now.