I am traveling with two friends. We are on one PNR, I have the 1K status they have none. I have been able to book seats for them with me in E+. I know that I will be eligible for CPU's on the domestic segments, not the International ones. If I leave the PNR alone, I take it that if I am upgraded the PNR will be split. My only concern is will they loose the E+ seating, and if so what can I do to prevent this?