Hi ... Yes, absolutely. You can cut it, just as you said and start over. I do this when my taller cactus get unsightly corking or other damage at the base. Don't throw that base away ... Keep caring for it and watch to see what it does. The base will likely put out a head of pups which you can remove to start new pots.

Maria Elena

Although you can do that, I would let it be. The shape is pretty nice and more in line with seed grown columnar cactus which can have a narrower base. Change in light after low light exposure usually produce weird and not so smooth shape transition. Cuttings can look stumpy and un-natural. But you may have to do it at some point, I would not just now if it were mine. I also don't mind some corking...

I have a tall column cactus like that. I inserted a green vinyl clad plant support next to it and used clear fishing line to loop around the cactus and the plant support. Now the cactus is very stable and the plant support is turned to the back.