I booked myself on a SFO-JFK-SFO itinerary at the end of June (S Class). I booked my friend on the same itinerary a couple of days later (S Class as well) so we have separate reservations. I have two RPUs that I'd love to use and the goal is for us to sit in the same cabin for each leg: both in BusinessFirst on the way over and both in Economy on the way back (or vice versa). Not surprisingly, upgrades with RPUs are currently waitlisted.

1/ Should I waitlist both of us now on one of the legs and hope that we both clear together (I'm Plat; she's General Member)? What if I'm the only one who clears? Can I decline the upgrade? Of course, if I do that, there is the risk that my exit row seat next to her might be gone...
2/ Should I wait until, say, 100 hours before departure and see if RPU upgrades are available for both of us at that point?
3/ Should I just check us in (making sure we're together in Economy) and wait until we get to the airport to see if we can both be upgraded on my RPUs?

Any insight/experience would be appreciated. Thanks!