I believe all instrument- and miles-supported upgrades clear first by premier status, not fare class. If you are on the same PNR, I believe your wife will inherit your 1K status. I'm sure others will jump in to correct if I'm mistaken.

I have no idea on how likely your GPUs are to clear IAH-EZE, though I did notice that WAS-IAH-EZE has P7 on 12/28, if you have any flexibility on dates—booking P outbound confirmed business and E return in coach on 1/6, for example, would be $2625 r/t, although that doesn't help jumpstart your 1K qualification for 2017. Unfortunately I do not see P inventory for the January return.