If anyone is still concerned I had the same problem. I've messaged CBOE and that is the solution -
You can find a list of all listed options here:
http://markets.cboe.com/us/options/market_statistics/symbol_reference/?mkt=cone&listed=1&unit=1&closing=1 . You'll want to sort by the symbol, looking for a begin string of '22' to locate options expiring in 2022.
I have tried and it works.
