Having had to be on crutches before, I understand the practicalities. With no weight bearing, you are further limited. Even with a retention holster, it is easier for someone who thinks you are an easy mark to make a try for your gun. You will fall more easily and be that much easier to overpower.
Your attention will be divided between being careful not to fall, and being aware of your surroundings to maintain control of your gun, etc.
If it was me, I would CC, but figuring out the best placement to avoid injury in case of a fall is the challenge.
You could always mod your crutches to contain a shotgun, Biden says that's best anyway.