Hi flywithmiles70,
Just a remark: being booked in Premium Economy fare class W allows you, in order to upgrade to business class, to use the fare bucket Z in addition to the O fare. Premium Economy A and S are only upgradable subject to availability in O in comparison.
Therefore, I suggest you set up an alarm notification on ExpertFlyer for both Z and O fare class openings. Having openings in Z is probably more likely than the Os.
For a JFK-CDG, a miles upgrade from W to Z will cost you 22,500 miles. Very reasonable.
Good luck!
-vinnyc