> Wikipedia suggests that temperatures in northern Europe would drop significantly + sea levels would rise, but is that all?

Depends on the drop and the rise.

Open a world map, and draw parallels passing where large Northern European cities are. [1]

E.g. Canada's Montreal roughly corresponds to Paris.

[1] Or this gif from reddit: https://preview.redd.it/dm7xwsmp3aa81.gif?format=mp4&s=a1673...