I am wondering if anybody can offer me a definitive answer regarding a dilemma I currently face on an upcoming United reservation with my family. I have searched these forums and I have even spoken with United reps over the phone and they themselves seem confused and unsure what happens.

I am a 1K and fly quite a bit by myself for business. I have an upcoming reservation with my family (my wife, my in-laws, and my children) to travel cross-country to visit other family members. As a 1K, I am able to book my entire traveling party up in the Premium Economy section without any upcharge, which is a perk I definitely appreciate. The 6 of us in my traveling party (the 5 of them and myself) are booked clear across a single row towards the front of the economy cabin.

Earlier last week, my boss informed me that there's a change in my work schedule, and I have to now be in the office for two of the days that I was supposed to travel. It's now not possible for me to fly on the flight with my family that i'm currently booked. My wife, children, and in-laws are still going to go, since they're a big enough party to look after things. But I want to know what will happen with the seat assignments that are already selected on the reservation.

Obviously, top priority is to make sure they keep the seats that are already assigned. (It's not even from purely a comfort perspective... if they are pushed back to regular economy, there aren't 5 seats across in any row... or even seats next to one another for that matter, it's all middle seats. I can't have my 3 and 5 year old sitting in the middle seats next to strangers). If I split the reservation and take myself off of it, does the computer automatically strip them of their seat assignments because it's no longer linked to my 1K status and there's no record of an upgrade purchase? I read on another forum that as long as there is no flight change or equipment change that they get to keep the seats, but if the seats have to be rebooked for any reason then they lose the premium economy. But when I asked about this scenario at the 1K customer service line, they didn't know the answer. I don't want to just go ahead and do it... I want to know with a pretty high degree of certainty what may happen so there's no unwelcome surprises.

Other option I suppose is to just not show up for the flight... check in their 5 seats but not check in myself.. and by the time I get canceled off the reservation they're already seated. The drawback I see in that, though, is whether they lose seats on the return flight, and I lose the entire ticket value rather than just eating a $200 change fee if i canceled ahead of time.

If all else fails, I will certainly pay for them to keep the premium economy seats... but as you can imagine I'd like to know how these other scenarios play out before I possibly needlessly shell out an extra $1000+. If I can cancel and they get to keep their seats (barring a flight change or something else odd), that's my best option. Also, I'm not at all concerned about them getting free bags or group 1 boarding. Only the seats matter since, as I mentioned, I don't want the kids separated and the rear of the aircraft does not currently offer that option. Thanks in advance for any advice you can provide.