If you are working now without too much difficulty you can probably continue for a long time. A lot depends on what type of work you do and how far you have to drive. Are you definitely getting AFO's? I do not have them yet, I am getting some type of brace, not those exactly, not sure yet about driving but my doctors are horrified that I drive as it is, but I only go in about a four mile radius, no highways. My reflexes are too slow for that.
I was a stay at home mom, taught English for a year three years ago, did fine but wasn't on much medication then. It really tired me out and could get very painful. The cold was the worst of it. I am 53 and this condition has slowly worsened throughout my life.
What type do you have, if they didn't give you a type is it myelin or axons? What are your symptoms now? It moves slowly but in my experience there can be big drop offs then a leveling off.
Physical therapy has helped with with the big drops- loss of strength in hands due to a flare up, arthritis in the spine, sprained ankle, etc. it is generally not considered to be very helpful in the long run for muscle atrophy which is inevitable, but I think it can delay things a bit. I have never regained normal function from it, but I have improved a little. It is important to have a therapist who understands even a little about CMT and doesn't push too hard or too long. Mine knows when to quit, and it isn't when they normally would. I stop regaining strength much sooner than without CMT.
You are right, it could be worse.

I have AFO's and I drive with no problem. I do not do physical therapy. If you do be certain that they know something about CMT or it could hurt you. As far as gaining strength, that would be the good muscles you still have not the atrophied dead muscles you have which you can do nothing about. There is a fine line as to how much you can exercise, etc. CMT progresses no matter what you do.

I have leveled off in a debilitating state. My hammer toes have no feeling and are curling more and more. I am numb to midcalf. Cold as ice until I have an episode of swelling and fire. That happens about once every 2 weeks. Still trying to figure out what triggers it. My hands are always numb and tingling. I exercise them at least 2 hrs a day using large metal balls and stress balls (the metal balls cause pain, stress ball.. not so much). I have no fine motor skills at this time. I have demyelinating as well as axonal. I am just beginning physical therapy. I have been doing low impact yoga to my ability.