AVERAGE temperature matters.
The gulf stream is a moderator. It keeps Britian and eastern Europe warmer in the winter than it deserves to be, but in the summer, has little effect.
What we are seeing now is a heat dome over the summer. IE, the AVERAGE ANNUAL temperature of Europe is going up, not the daily temperature.
If and when the gulf stream shuts down what will happen is Britian and western Europe will freeze in the winter.. in fact it may start to become covered in ice. Go look at any globe and look at where Britian exists compared to Russia and Canada, it is further north than Labrador. For all rights, it should be fozen in ice all winter. The reason it is mild, is because of the gulf stream.