If Germany's First World War battleships became Bismarcks

Replacing every German battleship with a fuel- and ammunition-unlimited Bismarck would create a technological and numerical shock that the Grand Fleet could answer only by risking nearly every available asset.

Question

What if every German battleship in the First World War became a Bismarck with unlimited fuel and ammunition?

Short answer

Germany might win the naval war unless Britain committed its entire fleet, including expendable mass torpedo and submarine attacks, to destroy them.

Notes

The scenario gives Germany modern 15-inch guns, radar, speed, protection, and numerous copies of a much later capital ship. This force could overwhelm contemporary British battleships and might change the outcome of the war at sea. Britain would still possess many destroyers, torpedo craft, and submarines, but using them effectively would require treating much of the light fleet as expendable. Fire-control technology and defensive systems matter as much as gun calibre when equipment is displaced across eras.