Here's my calculation with many naive assumption.
[...]
Total time = 4000 blocks / 144 blocks (total blocks in one day) = 27.77... days
27.7 days is very long time, so you better hope majority people won't move their vulnerable UTXO at similar time.
yeah and i figure normal day to day TXs on top of that.. so all those need to be squeezed in too.
but can say a TX from a quantum vulnerable addy to a quantum safe addy (to buy something say) get change back in a safe addy? at least
some day to day TXs would get rolled in for free
that way, kinda.