A few months ago we had similar thoughts. Fortunately we are both ok, but looking to the longer term we need a contingency plan - downsize, move closer to kids, stay where we are etc.
As I quite like where we live and ideally would prefer not to be a burden on the kids (in their 30s now) we looked at options in our current house - 4 bed detached extended at ground floor level.
- Stair lift. Seems like a lot of money for something really very simple. Stairs bend 90 degrees with mini landing adds to complexity. Permanent reminder of infirmity is unattractive.
- Convert attached workshop to downstairs bedroom. Plenty of square feet but building regs a costly problem - insulation, need to increase headroom. If I lose mobility to the point I can't manage stairs, then I would probably need a new hobby anyway
- Extend upstairs - main bedroom suite and lift. Most costly solution. Lift seems expensive but could be designed so that removal would just leave two large cupboards.
- Convert a single storey extension presently used as office/grandchild playroom into bedroom and en-suite. Cheaper options 2 and 3 and much less disruptive.
It is clear that stair lift and lift companies know most folk only act when a solution is time critical and charge accordingly. I suspect many act in haste and may subsequently regret the outcome.
With a plan (what to do IF), any impediments can be solved in good time reducing costs and timescales - plans drawn up, planning permission if required, understand costs rather than being surprised etc.