We are three people going from Copenhagen-Philadelphia. I will be staying there because I have permission to work but the other two passengers need to go on to Rome within 20 days because they have permission only for tourism.
Buying one-way tickets Copenhagen-Philadelphia is much more expensive than buying multi-destination tickets Copenhagen-Philadelphia-Rome. I will not take the flight Philadelphia-Rome and do not care if I lose money for it as in any case it would be cheaper than one-way options.
My only concern is: might the other two passengers experience trouble at check-in because one passenger does not show up?