I think you would probably agree that a change in the size of the House is not likely to occur through legislation or a Constitutional amendment proposed in Congress but would require an Article V Constitutional Convention.
The Congress, whenever two thirds of both houses shall deem it necessary, shall propose amendments to this Constitution, or, on the application of the legislatures of two thirds of the several states, shall call a convention for proposing amendments, which, in either case, shall be valid to all intents and purposes, as part of this Constitution, when ratified by the legislatures of three fourths of the several states, or by conventions in three fourths thereof...
So.....how would you word your proposed amendment?