I think quicksavedave has got the right balance. Predicting what may happen is fun, but a little like placing a bet on a horse.
I also think 100 year mortgages is more media hearsay. There probably were instances in Japan, but I doubt it was the rule. It is generally known that an ageing polulation brings it’s own problems. You are just going to compound the problem by quick fixes.
My view is let the market play out. There will be winners and loosers, a lesson learnt and if needs be, tighter control and regulation on lending for the future.