The problem is that even a Constitutional Convention gives more power to land than people.

Specifically in the case of a Constitutional Convention 2/3 of states have to agree to have one and 3/4 of states have to agree to any changes.

You'd have an easier time convincing the federal government to condense a few states - we don't really need TWO Dakotas, and Montoming seems like a good idea. Maybe also split California into a few pieces. The whole "land over people" thing is only really a problem because a couple of states blow the curve - House apportionment is done in a fashion that mathematically minimizes the average difference in people/representative between states while having a fixed number of representatives, but California blows the curve by being so utterly massive compared to any other state and there just not being enough representatives to go around. So all but a few states are pretty close in terms of people/representative, a couple are sitting at the 1 representative minimum while being tiny, and California blows the curve on the other side.

Either increase the House size, merge some of the smallest states, split California up or all of the above - and all of those can be done without passing an amendment.

Of course, then Texas will invoke the clause in the Joint Resolution for Annexing Texas to the United States and split itself into five states, each of which gets its own Senators and whatever number of Representatives the math would work out to.