Any answer to the question would be a new interpretation, since the clause hasn’t previously been litigated.
But you can clearly amend the powers of the Senate, including abolishing all of them. And/or create a third house of Congress, without equal per-state representation.
I wouldn’t be so sure; it would require getting states to vote against their narrow parochial interests, but it's not inconceivable that it could happen. It would probably take a crisis of legitimacy in which the disaffection of the underrepresented states was sufficient to threaten the viability of the union, though.
But you can clearly amend the powers of the Senate, including abolishing all of them. And/or create a third house of Congress, without equal per-state representation.