The size of the CV is governed by the design of the front end. Starting with the stud pattern of 114.3x6 restricting the size of the hub, and the size of the axles, plus the amount of space with steering mechanisms, suspension and supports all coming into the equation.
There is another way (and you'll get TONS more benefit from this). Put an e-locker up front. Can drop an auto locker in too, they're cheaper but you don't get to choose when they activate. Air lockers are also a possibility and if you don't have a compressor yet then lean towards the air locker with onboard compressor + tank, you'll kill two birds with that stone.
Anyway, fully locked you'll find that you can lift a wheel and that lifted wheel will turn over at the rate of the wheel on the ground. You'll also have power delivered to the wheel on the ground and not spent spinning the other one.
You'll be like "obstacles schmobstacles, point me at the mountain!".