GM Upgrade issue

Not really an issue, more of a 'how can I do this...'

I'm GM, and am travelling LHR-JFK, LGA-MCO, MCO-JFK-LHR just after Christmas; spending a few days in NYC then New Year in Orlando.

I'm travelling with my partner and two children (3 years and 6 months)

My partner and eldest have SkyMiles accounts but no status.

I requested to be put on upgrade list, but because I have 2 companions they cannot do it.

I've considered splitting the PNR but think it would be a bad idea.

The tickets are all U classes, so don't even think I will have the opportunity to pay for upgrade!?

Do I have any options?

What are the chances of being upgraded without being on 'the list'?

Thanks,

Peter