Well, this change in particular was actually a change back to the norm:
https://www.science.smith.edu/climatelit/the-effects-of-the-little-ice-age
They used to have fairs on the Thames in winter back then as well.
"If history is to change, let it change! If the world is to be destroyed, so be it! If my fate is to be destroyed...I must simply laugh!!."- Magus