I have 20,000 ANA miles that are set to expire in about a year. The plan I had had to use them (on a partner flight in Europe) may not work out, so I'd like to somehow get the expiration date of the miles extended so that I can use them further down the road.

Just checked ANA's website; could not find the answer to this question: Can the expiration date of ANA miles be extended (e.g. by buying something from an ANA online shop, if one exists; or by buying some ANA miles)?

I seem to recall having read somewhere in the past that ANA miles expire when they expire, and cannot be extended. Would someone know for sure?