Originally Posted by
mmff
One extra point I am now worrying about: what happens if I am affected by IRROPs on my way from OPO to OSL? I wouldn't want to be rebooked directly to NYC, but from the flight grouping in the app (different from what I see in the fare rules) that seems to be what they would do.
The fare rules are only used for computing the ticket price; they have no impact upon how rebooking would go.
I would not touch that ticket on a bet. (I also wouldn't have booked it; I'd have booked it as separate tickets, since you're not making use of the Excursionist Perk).
If you still see availability for each leg at the price levels you want, I would definitely cancel and rebook, and I'd rebook each leg separately. If the miles aren't redeposited instantly, which is standard practice, a call to the MileagePlus Service Center can rectify that.