Would saving money outside of banking system be able to reduce monetary base?
Options 1-2 do not reduce the monetary base. “Money in circulation” are all notes/coins that were issued to the private sector and not returned. 

There is no way of measuring how many transactions notes/coins support (or whether they have been destroyed). So reducing “circulation” has no effect on published statistics.

Option #3 would reduce the monetary base if the money is returned to the central bank.