in jars; I find about three years (for weed) tops (simply stored in a cool, dark place). By then, flavour and strength have started to diminish some.
Vacuum sealed; I've had 4 year old weed that was still nice and the flavour had matured/cured in a good way (it was more 'earthy'). The high was still great too. Thats the oldest vac sealed weed I have tried.
I think 'Cob Curing' or just turning older weed into hash (for long term storage) is a fine idea
Hash is much easier to store long term (imo). And, I've had 20+ year old hash that was just great and super smooth.
Otherwise, I would recommend vacuum sealing (leaving a 'little' air in the bag, so as not to crush the buds) and putting in the back of the fridge freezer.
You could also vac seal, place in sealed containers and bury them (about elbow deep - its an old measurement
Just depends on your circumstances.