Or winter sufficiently close to the north pole (i.e. significant proportion of Europe). Days get short and it’s usually cloudy so solar becomes extremely inefficient.
Over-provisioning by 7x might not be extremely practical.
I guess there is a lot of space in Spain that could be filled with solar panels (production only falls by ~50% there in winter so it’s not to bad) but there is certainly not enough grid capacity to transfer all of that north (and building new infrastructure is painfully slow and expensive in Europe so it will take a few decades to solve that)
My point is that solar is only a part of the solution and wind/etc. is probably more practical and more important in much of Europe.
Or winter sufficiently close to the north pole (i.e. significant proportion of Europe). Days get short and it’s usually cloudy so solar becomes extremely inefficient.