If Bismarck reached a French Atlantic port

What happens if Bismarck reaches a French Atlantic port after Sheffield is not attacked?

Britain would face a larger capital-ship concentration in France, requiring stronger surveillance and a sustained effort to destroy it before separate or combined breakouts.

A French Atlantic port would leave Bismarck exposed to concentrated British bombing and naval attack. Her presence alongside Scharnhorst and Gneisenau would tie down more of the Home Fleet while Tirpitz still required watching farther north. That division could force difficult decisions about transferring ships from other theatres, with Warspite raised as one possibility. A subsequent Channel Dash would be less likely to encounter the same British dispositions because the Royal Navy would have stronger reasons to maintain its own aircraft, submarines, and surface forces around the concentration. Three capital ships leaving separately could require three simultaneous pursuits, while a combined sortie with escorts could threaten a fleet engagement. The danger supplies the rationale for a much larger effort to destroy the ships in harbour.