It can be done, but it takes lots of digging and creativity. I’ve gotten 5 U awards on AA starting in Seattle and going to Europe, and I’ve done it twice in 2018. I got SEA-DFW-LHR-PMI in August and SEA-LAX-LHR in December. We flew back via CAI on cheap one way J fares we found ex-CAI (which are no longer available) which we upgraded to F (CAI-LHR-LAX) on the trans atlantic (AA) sector. You have enough miles for the AA NA-EU biz awards for 4 pax one way. Maybe start looking for those and then see if you can find the other direction with your other points/miles and some cash+upgrades.