27XP is not hard.

One return flight in eurobiz to anywhere in europe.

Alternatively, one return flight in KLM in Y to anywhere in europe apart AMS + either 70euros of SAF OR link your accor membership and get the bonus OR one more Y trip to wherever. (Not domestic)

Are you sure your FB renewal is end of december? FB is not a calendar year program. It could be any month.

If you want to start playing the xp game beyond that, consider departing from BRU, ZWE, GVA, anywhere but CDG. Or consider ITA flights.