Then the reasoning in Reynolds v. Sims must be incorrect. If representation based on geography is unconstitutional for the states, it stands to reason that it is unconstitutional for the federal government as well.
Reynolds is incorrect and the court should have never denied to the states, what the constitution reserves for itself to engage in at the federal level. This is the product of a majority that itself was keen on overwriting the explicit word of the Constitution and presumed as a matter of progress that the US Senate would one day be abolished or reformed, just that they themselves didn't view themselves as having the power to do so.
The ruling should have required that at least one chamber of each state represent its people in accordance with one man, one vote, not both.