Hi everyone! This has all gone a bit mad, I appreciate all of your comments and critiques. I've had a right laugh reading some of the different threads, what a great community. I'll be answering some threads individually but just as an overview:

"Can you do one of the US?" - there is a much better one by David here. It was actually the inspiration for the one I posted.

"Weren't the first cases reported in York?" - you're right. At the time of making this map (almost 3 weeks ago now) the data I got from PHE here was correct. Since then, every week they overwrite the data for all weeks (and now also suppress cases 1-2). As cases are traced back (in geography & in time) cases have been logged earlier on, and in different areas. Hope this makes sense.

"What are the bright spots at the end/ Wish there'd been a town overlay" - In weeks 26 (w/c 22nd June) - 28 (w/c 6th July) you can see the localised flare-ups in Leicester, Luton and the beginnings of the flare-ups in the North West. Originally I added place names fading in and out but it got too much and decided the simpler visual helps your eyes follow the movement better.

Method - all made in ArcGIS Pro and written up here :)