I'm 71. First, I had CTS on my left (non-dominate) hand, which was not yet severe. After two weeks I was mostly functional, but I wasn't supposed to lift more than 2-5 lbs. That was to be followed by 6 weeks physical therapy. I was fine.

Then two weeks after the left hand surgery, they did my right hand, combined carpal tunnel and a thumb joint (CMC) arthroplasty. The carpal tunnel on the right was severe and developed massive scar tissue around the incision. That caused "nerve glide" and "tendon glide" issues, which turned into full blown tendonitis from the tips of my fingers to the inside of my elbow. Debilitatingly painful. PT was delayed. At 3-1/2 months post-surgery, I'm still in a lot of pain and have limited functionality. I think I worsened the scar issue by trying to do too much too soon after surgery, too. It's taking forever to break up the scar tissue to resolve the tendonitis.

I wouldn't have been able to use a cane at all, and still couldn't. (However, some of my lack of function is from the thumb surgery.) Given that yours is severe, I'd take it slow, but do PT and massage as early as possible, and be careful how much weight you'd be bearing on that hand using the cane.

I'd suggest having a Plan B, maybe a walker, temporarily. Hope I haven't scared you unnecessarily.

Wish you the best of luck! ❤️