Even without her disability - I still think immigration is going to be next to impossible for you given your age. That's a very big barrier unfortunately because of how many points you lose under Express Entry. I believe most of the Provincial Nominee Programs won't even consider your application due to your age. If you want to try the EE route, I would apply from the US now rather than moving to Canada first. Don't wait any longer. You'll want to have at least 430 points to have a decent chance of being selected out of the pool. Of course even if you're selected out of the pool - there's still the medical to pass.
For your wife's health care and social care needs, you're still not looking at it quite the right way - CIC will have a different view. Understand that once she is a PR, she will have access to the full health and social care system Canada has to offer - and that's how CIC will assess her medical admissibility. So if you are providing therapy now that she should ideally be getting from a registered therapist - CIC will assign a cost to that as if this was being provided by a therapist. They will say medications aren't the only expense and will also assume that she at a minimum has a few doctor visits each year (as any normal person would) and a few specialist visits each year which involve tests (obviously this would be expected of someone with her condition). So they will factor these cost in as well. They will also consider what would happen if her condition deteriorated sufficiently that you needed some at home assistance (i.e. nurses aide) to check in on her while you're at work. Lastly, they will consider whether she may reasonably need some hospitalization over the course of the next 10 years. Again, they won't just look at her condition now - they will consider how her condition is expected to deteriorate over the next decade. And they won't just assess the services you are using now - they will assess what services your wife will reasonable use once a PR.
She does not receive nor ideally need physical therapy, as her condition only affects visual and memory more than it does, motor skills. She has approximately 2-3 PCP doctors checkups every year, and as far as tests there is no longer a need to take imaging or testing as her condition has progressed far already. All of her neurologist visits are done with specialists outside the US and Canada. Nurses would not be necessary or preferred as I provide all of her care with eating, dressing, recreation, and helping her to sleep. ER visits are possible, but because of nothing related to her condition.